JP2012031803A - Vane pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vane pump in which high gas-tightness can be achieved between a supply hole and a discharge hole.SOLUTION: A vane pump is constituted by a rotor 38 radially formed of three or more vane grooves 37 each of which is rotated and driven in a predetermined direction around an axis of rotation 33, has a right cylinder-like outer circumferential surface, and is orthogonal to the axis of rotation 33, three or more vanes 39 fitted into respective vane grooves 37 of the rotor 38 movably along respective vane grooves 37, and a casing having a housing space 40 which houses therein the rotor 38 and the plurality of vanes 39, and first to fourth inner circumferential surfaces which have different radii for every 90 degrees relative to the axis of rotation 33 and face the housing space.

Description

  The present invention relates to a vane pump that delivers a transfer material such as a food material.

  FIG. 9 is a front view showing the internal structure of the vane pump 1 of the prior art. In the figure, the lid is omitted for easy illustration. The vane pump 1 of the prior art is connected to one axial end portion of the rotary shaft 2 and has a rotor 4 formed with a vane groove 3 orthogonal to the rotary axis 2A, and a pair of vanes 5 movably fitted in the vane groove 3. The rotor 4 is rotatably accommodated in a housing space 6 having an axis that is eccentric with respect to the rotational axis 2A, and a plurality of pump chambers 7a to 7d partitioned by the vanes 5 are provided around the rotor 4. The casing 10 is formed, and the supply hole 8 and the discharge hole 9 communicating with the pump chambers 7a to 7d are formed by the rotation of the rotary shaft 2, and the casing 10 is detachable from the casing 10 at one end in the axial direction of the rotor 4. And a lid (not shown) provided.

  The casing 10 has first to fourth inner peripheral surfaces 11a to 11d. The first inner peripheral surface 11a is composed of a part of a right cylindrical surface having a first radius r1 centered on the rotation axis 2A, and the second inner peripheral surface 11b is the first radius r1 centered on the rotation axis 2A. It consists of a part of a right cylindrical surface having a smaller second radius r2. The third inner peripheral surface 11c connects the boundary position p1 between the first inner peripheral surface 11a and the third inner peripheral surface 11c and the boundary position p2 between the third inner peripheral surface 11c and the second inner peripheral surface 11b. The fourth inner peripheral surface 11d is composed of a part of a right cylindrical surface with three radii r3, and further includes a first inner peripheral surface 11a, a fourth inner peripheral surface 11d, a boundary position p3, a fourth inner peripheral surface 11d, and a second inner surface. It consists of a part of a right cylindrical surface with a fourth radius r4 connecting the boundary position p4 with the peripheral surface 11b. Each vane 5 is selected to have a length capable of sliding each tip on the first to fourth inner peripheral surfaces 11a to 11d by the rotation of the rotor 4 in the direction of arrow A.

JP-A-6-346859

  However, in the vane pump 1 of the prior art, among the pump chambers 7c, 7a, 7d existing between the supply hole 8 and the discharge hole 9 on the downstream side in the rotation direction A of the rotor 4, between the supply hole 8 and the discharge hole 9, What is always kept in a space closed by each vane 5 is only the pump chamber 7a, that is, the region between the boundary positions p1 and p3 where the first inner peripheral surface 11a is formed, and this first inner peripheral surface. Since only one vane 5 always slides on 11a, high liquid-tightness cannot be obtained between the supply hole 8 and the discharge hole 9, and the transferred material in the discharge hole 9 is pushed out during operation. Leakage between the first inner peripheral surface 11a and each vane 5 passing through the first inner peripheral surface 11a due to the differential pressure between the pressure and the supply pressure lower than the extrusion pressure of the transferred material in the supply hole 8 Depending on the physical properties such as the viscosity of the transferred material, the In some cases the stability is lowered.

  An object of the present invention is to provide a vane pump capable of obtaining high liquid tightness between a supply hole and a discharge hole.

In the present invention, three or more vane grooves (37) that are rotationally driven in a predetermined rotation direction (A) around a rotation axis (33), have a right cylindrical outer peripheral surface, and are orthogonal to the rotation axis (33). A radially formed rotor (38);
Three or more vanes (39) that are movably fitted along the vane grooves (37) in the vane grooves (37) of the rotor (38);
The first to fourth inner peripheral surfaces (20, 21) having an accommodating space (40) in which the rotor (38) and the vanes (39) are accommodated and having different radii every 90 ° with respect to the rotation axis (33). , 22, 23) includes a casing (41) formed facing the housing space (40),
The first inner peripheral surface (20) is composed of a part of a right cylindrical surface having a predetermined first radius (R1) centered on the rotation axis (33),
The second inner peripheral surface (21) is opposite to the first inner peripheral surface (20) with respect to the rotation axis (33), is smaller than the first radius (R1), and is The sum of one radius (R1) consists of a part of a right cylindrical surface with a second radius (R2) equal to the length of each vane (39);
The third inner peripheral surface (22) has an end on the upstream side in the rotational direction (A) of the first inner peripheral surface (20) and a downstream side in the rotational direction (A) of the second inner peripheral surface (21). The boundary position (P2) between the third inner peripheral surface (22) and the second inner peripheral surface (21) and the first inner peripheral surface (20) and the third inner peripheral surface (22). Consists of a curved surface connecting the boundary position (P1) and protruding radially outward,
The fourth inner peripheral surface (23) includes an end on the downstream side in the rotational direction (A) of the first inner peripheral surface (20) and the upstream side in the rotational direction (A) of the second inner peripheral surface (21). The boundary position (P3) between the first inner peripheral surface (20) and the fourth inner peripheral surface (23), the fourth inner peripheral surface (23), and the second inner peripheral surface (21). Consisting of a curved surface connecting the boundary position (P4) of FIG.
The casing (41) opens on the third inner peripheral surface (22) and opens on the supply hole (82A) to which the transferred product is supplied and on the fourth inner peripheral surface (23). The vane pump is provided with a discharge hole (82B) for discharging.

  According to the present invention, when one vane (39) is disposed at the boundary position (P1) that is the inflection point between the first inner peripheral surface (20) and the third inner peripheral surface (22), Another second vane (39) adjacent to the downstream side in the rotational direction (A) with respect to the one vane (39) is an inflection between the first inner peripheral surface (20) and the fourth inner peripheral surface (23). The second vane (39) is disposed on the upstream side in the rotational direction (A) with respect to the boundary position (P3) as a point, and the second vane (39) is a boundary between the first inner peripheral surface (20) and the fourth inner peripheral surface (23). During the period until reaching the position (P3), the two vanes (39) are in sliding contact with the first inner peripheral surface (20), and the transfer path between the supply hole (82A) and the discharge hole (82B) is highly liquid-tight. Can be blocked by sex.

It is the front view which removed the cover body 32 of the vane pump 31 of one Embodiment of this invention. It is sectional drawing of the vane pump 31 seen from the cut surface line II-II of FIG. FIG. 4 is a front view showing a rotor 38. It is sectional drawing seen from the cut surface line IV-IV of FIG. It is a front view showing vane 39A. It is a front view which shows vane 39B. It is a front view showing vane 39C. It is a side view of vane 39C. It is a front view which shows the internal structure of the vane pump 1 of a prior art.

  FIG. 1 is a front view showing a vane pump 31 according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view showing the configuration of the vane pump 31 in FIG. 1, as viewed from the section line II-II in FIG. It is sectional drawing. Note that FIG. 1 is shown with the lid 32 omitted for ease of illustration.

  The vane pump 31 is connected to a rotation shaft 34 that is rotationally driven in the rotation direction A around the rotation axis 33, a bearing portion 35 that rotatably supports the rotation shaft 34, and one axial end portion 36A of the rotation shaft 34. A rotor 38 in which a plurality of (three in this embodiment) vane grooves 37 perpendicular to the rotation axis 33 are formed, three vanes 39A, 39B, 39C provided in the vane grooves 37 of the rotor 38, and the accommodation space 40 A casing 41 that rotatably accommodates the rotor 38, a lid body 32 that is detachably provided on the casing 41, and a seal portion 44 that is provided at a connecting portion between the rotating shaft 34 and the rotor 38 are included. The above-described axial direction is parallel to the rotation axis 33.

  In the following description, the rotating shaft 34 of the vane pump 31 will be described as being driven to rotate in the rotational direction A that is clockwise when viewed from the left in FIG.

  The rotation shaft 34 is coaxially connected to the first rotation shaft portion 51 and one axial end portion of the first rotation shaft portion 51, and has a second rotation shaft portion having an outer diameter larger than the outer diameter of the first rotation shaft portion 51. 52, a third rotary shaft portion 53 that is coaxially connected to one axial end portion of the second rotary shaft portion 52 and has an outer diameter larger than the outer diameter of the second rotary shaft portion 52, and the axis of the third rotary shaft portion 53 A fourth rotary shaft portion 54 having an outer diameter smaller than the outer diameter of the third rotary shaft portion 53 and a first rotary shaft portion 54 coaxially connected to one end portion in the axial direction; The fifth rotating shaft portion 55 having an outer diameter smaller than the outer diameter of the rotating shaft portion 54 and the one end portion in the axial direction of the fifth rotating shaft portion 55 are coaxially connected and smaller than the outer diameter of the fifth rotating shaft portion 55. And a sixth rotating shaft portion 56 having an outer diameter.

  A rotor 38 is detachably connected to the sixth rotation shaft portion 56 of the axial end portion 36 </ b> A of the rotation shaft 34 coaxially with the rotation shaft 34. A key groove 57 extending in the axial direction is formed in the sixth rotation shaft portion 56, and a screw hole 58 is formed coaxially with the rotation axis 33 at one end portion in the axial direction.

  The rotor 38 is connected to the first shaft portion 61 connected to the rotation shaft 34, and is coaxially connected to one axial end portion of the first shaft portion 61, and has a second outer diameter larger than the outer diameter of the first shaft portion 61. The shaft portion 62 includes a rotor body 63 that is coaxially connected to one axial end portion of the second shaft portion 62 and has an outer diameter larger than the outer diameter of the second shaft portion 62.

  The first shaft portion 61 of the rotor 38 is formed with a fitting hole 64 coaxially with the rotation axis 33 and extending from the other axial end surface to one side in the axial direction. The inner circumferential portion facing the fitting hole 64 has an axial direction. A key groove 65 extending in the direction is formed.

  3 is a front view showing the rotor 38, and FIG. 4 is a cross-sectional view taken along the section line IV-IV in FIG. The rotor body 63 is generally a short columnar shape, and its outer peripheral surface is included in the right cylindrical surface. In the rotor body 63, three vane grooves 37A, 37B, and 37C having a concave cross section intersecting on the rotation axis 33 are formed radially, and the intersections of the vane grooves 37A to 37C and the fitting hole 64 are: The first shaft portion 61 and the second shaft portion 62 communicate with each other through an insertion hole 66 formed coaxially with the rotation axis 33.

  Each of the vane grooves 37A to 37C is a straight line passing through the intermediate portion in the width direction of the vane groove 37A, parallel to the extending direction of the vane groove 37A, and orthogonal to the rotation axis 33, and the width of the vane groove 37B. A straight line passing through the intermediate portion in the direction and parallel to the extending direction of the vane groove 37B and perpendicular to the rotation axis 33, and a straight line passing through the intermediate portion in the width direction of the vane groove 37C, the vane groove 37C The angle θ formed by the straight line L3 that is parallel to the direction in which the axis of rotation is perpendicular to the rotation axis 33 is 60 °.

  The sixth rotation shaft portion 56 of the rotation shaft 34 is inserted into the fitting hole 64, and a key 57 formed on the sixth rotation shaft portion 56 is fitted into the key groove 65, so that the rotor 38 and the rotation shaft 34 are mutually connected. Is prevented from rotating.

  With the rotor 38 and the rotary shaft 34 thus prevented from rotating together, the rotor fixing bolt 67 is screwed into the screw hole 58 formed in the sixth rotary shaft portion 56 through the insertion hole 66. Is done. Thereby, the rotor 38 and the rotating shaft 34 are fixed to each other. The intersections of the vane grooves 37 </ b> A to 37 </ b> C are formed as right columnar spaces because the rotor fixing bolts 67 communicate with each other so as to be freely movable in the axial direction.

  The axial length of the sixth rotating shaft portion 56 is selected to be smaller than the axial length of the fitting hole 64 formed in the first shaft portion 61 of the rotor 38, and the sixth rotating shaft portion 56 is fitted. When fitted into the hole 64, the other axial end 42 </ b> B of the rotor 38 contacts and is fixed to one axial end of the fifth rotating shaft 55.

  The insertion hole 66 has different inner diameters at one end and the other end in the axial direction. The inner diameter of the one end in the axial direction is selected to be larger than the inner diameter of the other end. The second shaft portion 62 is immersed. In addition, an O-ring 68 is attached to the rotor fixing bolt 67, thereby preventing the transferred material from leaking from between the rotor fixing bolt 67 and the insertion hole 66.

  5 is a front view showing the vane 39A, FIG. 6 is a front view showing the vane 39B, FIG. 7 is a front view showing the vane 39C, and FIG. 8 is a right side view of the vane 39C.

  As shown in FIGS. 5 and 6, the vanes 39A and 39B are made of stainless steel, or a plate made of polyetheretherketone (abbreviated as PEEK), polytetrafluoroethylene (abbreviated as PTFE), or other resin. It has a substantially U-shape with the middle part of the member cut out. The vane 39A has a notch 69A, and the vane 39B has a notch 69B. Further, as shown in FIG. 7, the vane 39C is formed by using an intermediate portion in the long side direction of a rectangular plate member made of stainless steel, polyether ether ketone, polytetrafluoroethylene, or other resin, on both sides in the short side direction. It is formed in a substantially I-shape cut out from the shape. The vane 39C has two notches 69C and 69D.

  The vanes 39A, 39B, 39C are arranged in a posture in which the short side direction is parallel to the rotation axis 33, and the vanes 39A, 69B face each other between the vane 39A and the vane 39B. In a state where 39C is disposed, the rotor 38 is attached to the vane grooves 37A to 37C intersecting each other. As a result, each of the vanes 39A to 39C can be displaced along the radial direction of the rotor 38.

  Thus, when each vane 39A, 39B, 39C is mounted on the rotor 38 and rotated in the rotational direction A within the casing 41, one surface 39A1, 39B1, 39C1 in the thickness direction of each vane 39A, 39B, 39C is Since the vane grooves 37A, 37B, and 37C of the rotor 38 abut against one inner surface 37A1, 37B1, and 37C1 facing the upstream side in the rotational direction A and are pressed in the rotational direction A, the thicknesses of the vanes 39A, 39B, and 39C Between the other surfaces 39A2, 39B2, 39C2 in the direction and the other inner surfaces 37A2, 37B2, 37C2 facing the vane grooves 37A, 37B, 37C of the rotor 38 from the downstream side in the rotation direction A, respectively. A slight gap is formed so that 39C can move.

  The length of each vane 39A, 39B, 39C in the long side direction is L4, the length in the short side direction parallel to the rotation axis A of the rotor body 63 is L5, and the casing 41 accommodates the rotor body 63 accommodated therein. When the length in the axial direction parallel to the rotation axis A of the space 40 is L6, the lengths L4, L5, and L6 are selected in a relationship of L6> L4> L5.

  In other embodiments of the invention, the vanes 39A, 39B, 39C may be formed of materials such as polytetrafluoroethylene, polyetheretherketone, and ultra high molecular weight polyethylene.

  Referring again to FIGS. 1 and 2, the casing 41 rotatably accommodates the rotor body 63 in a housing space 40 having an axis that is eccentric with respect to the rotational axis 33. Around the rotor main body 63, pump chambers 81a to 81f partitioned by the vanes 39A to 39C between the inner peripheral surface 80 of the casing 41 (in general terms, "pump chamber 81" may be described). ) Is formed.

  The housing space 40 of the casing 41 is surrounded by the first to fourth inner peripheral surfaces 20 to 23. The first inner peripheral surface 20 includes a rotation axis 33 and is a single cylindrical surface having a first radius R1 centered on the rotation axis 33 over a range of an angle θ1 formed by two virtual planes X and Y orthogonal to each other. Consists of parts.

  Further, the second inner peripheral surface 21 is opposite to the first inner peripheral surface 20 with respect to the rotation axis 33, that is, is axially symmetric and is a single cylindrical surface having a second radius R2 smaller than the first radius R1. And is formed over a range of the angle θ2. Therefore, the first inner peripheral surface 20 and the second inner peripheral surface 21 are coaxial.

  The third inner peripheral surface 22 is formed of a part of a substantially cylindrical surface that is a curved surface convex outward in the radial direction with a third radius R3, and is upstream of the first inner peripheral surface 20 in the rotational direction A of the rotor 38. The inflection point P1 on the side and the inflection point P2 on the downstream side in the rotation direction A of the rotor 38 of the second inner peripheral surface 21 are formed over the range of the angle θ3.

  The fourth inner peripheral surface 23 is formed of a part of a substantially straight cylindrical surface that is a curved surface convex outward in the radial direction of the fourth radius R4, and is downstream of the first inner peripheral surface 20 in the rotational direction A of the rotor 38. The inflection point P3 and the inflection point P4 on the upstream side in the rotation direction A of the rotor 38 of the second inner peripheral surface 21 are formed over the range of the angle θ4. These angles θ1 to θ4 are each 90 °.

  In determining the third and fourth inner peripheral surfaces 22, 23, the virtual plane Y passing through the rotation axis 33 and the virtual plane X including the rotation axis 33 are orthogonal to each other, two of these virtual planes Y, X, etc. On the dividing line 24, points P5 and P6 that are half the length L4 of the vanes 39A to 39C (= L4 / 2) from the rotation axis 33 are adjacent to both sides in the circumferential direction of the points P5 and P6. The arc centers Q1, Q2 of the third and fourth inner peripheral surfaces 22, 23 are set so as to pass through the inflection points P1, P2; P3, P4.

  The casing 41 is provided with a supply hole 82A that opens upward and a discharge hole 82B that opens laterally.

  The supply hole 82A is opened facing the pump chambers 81e and 81f, and the discharge hole 82B is opened facing the pump chambers 81b and 81c. Accordingly, the transferred material supplied from the supply hole 82A is supplied to the two pump chambers 81e and 81f, and the rotational direction A is increased while the volume is increased as the rotor 38 is rotationally driven around the rotational axis 33 in the rotational direction A. The transferred materials in the pump chambers 81e and 81f that are moved to (1) are sequentially transferred in the same direction and moved to positions corresponding to the pump chamber 81a in FIG. Further, when the rotor 38 rotates in the rotation direction A, each pump chamber 81 reduces the volume from the discharge chamber 82B to the downstream pump chamber 81b from the rotation direction A upstream pump chamber 81a while reducing the volume. Immediately after the state of 81c is reached and the vanes 39A to 39C have passed the inflection point P3 between the first inner peripheral surface 20 and the fourth inner peripheral surface 23 to the downstream side in the rotational direction A, The transferred material is extruded into the discharge hole 82B.

  When each of the vanes 39A to 39C reaches the position indicated by the pump chamber 81d, the outer peripheral surface of the rotor 38 and the second inner peripheral surface 21 face each other with a minute gap of, for example, about 0.3 mm. The volume of the pump chamber 81d is almost zero. By repeating such an operation continuously, the transferred material in each of the pump chambers 81e, 81f → 81a → 81b → 81c → 81d is transferred at a substantially constant flow rate without causing significant pulsation.

  The casing 41 is formed with an opening 85 to which the lid body 32 is attached at one end 84A in the axial direction. In addition, a rotor bearing portion 86 is formed at an intermediate portion in the axial direction of the casing 41.

  The casing 41 is integrally assembled to a bracket 121 described later. Joint portions 87A and 87B are formed on the upper and side portions of the casing 41 where the supply hole 82A and the discharge hole 82B are formed. Further, a stuffing box portion 88 connected to the rotor bearing portion 86 is integrally formed at the other axial end portion 84 </ b> B of the casing 41. In another embodiment of the present invention, the stuffing box portion 88 may be formed separately from the casing body extending from the rotor bearing portion 86 to the axial one end portion 85 and detachable by a fastening component such as a bolt. Good. Details of the stuffing box 88 will be described later.

  In the housing space 40 of the casing 41, the rotor main body 63 of the rotor 38 having the rotation axis 33 in the horizontal direction has a constant cross-sectional area with respect to the inner peripheral surface 80 of the casing 41 in the ¼ circumferential section 100. It is provided with its own transfer path. In the ¼ circumferential section 100, the rotor body 63 and the inner peripheral surface 80 of the casing 41 are coaxial and set in an arc shape having different radii.

  In the casing 41, supply holes 82 </ b> A and discharge holes 82 </ b> B are formed in the quarter circumferential sections 101 and 102 on both sides of the quarter circumferential section 100, respectively, toward the sections 101 and 102. The remaining 1/4 circumferential area 103 is formed with a slight gap so as to face the outer peripheral surface of the rotor body 63.

  The rotor bearing portion 86 in the casing 41 is formed coaxially with the rotation axis 33, and supports the second shaft portion 62 of the rotor 38 via a cylindrical bush 89. The bush 89 is formed of a material such as polytetrafluoroethylene, stainless steel, copper alloy, or PEEK.

  An annular O-ring groove 91 into which the O-ring 90 is fitted is formed at one end 84 </ b> A in the axial direction of the casing 41 at a radially outward portion perpendicular to the rotation axis 33 of the opening 85. A plurality of screw holes 92 are formed in the casing 41 at intervals in the circumferential direction outward in the radial direction of the O-ring groove 91.

  A disc-shaped lid 32 is detachably fixed to one end 84 </ b> A in the axial direction of the casing 41 by a lid mounting body 99 including an eyenut 98 and a screw hole 91, and the lid 32 opens the casing 41. Part 85 is blocked.

  An insertion hole is provided in the outer peripheral portion of the lid body 32 with an interval in the circumferential direction. The lid body 32 has the O-ring 90 sandwiched between the lid body 32 and the casing 41, and a plurality of lid body mounting bolts are provided at one end 84A in the axial direction of the casing 41 through the insertion hole. The screw hole 92 is screwed. The O-ring 90 prevents the transferred material in the casing 41 from leaking between the casing 41 and the lid body 32.

  The eye nut 98 is a nut in which an annular body is integrally provided at the end of the cap nut. Even if a special tightening tool is not used for tightening and removing, it is possible to easily tighten and remove by inserting a rod member into the annular body and rotating it around the axial direction of the eye nut 98. A person can easily attach or remove the lid 32 to or from the casing 41.

  An embedded bolt is screwed into a screw hole 92 formed in the casing 41, and an eye nut 98 is screwed to the embedded bolt to fix the lid 32. Therefore, the lid 32 can be fixed to the casing 41 with high accuracy by inserting the embedded bolt into the insertion hole of the lid 32 and positioning the eye nut 98.

  The rotating shaft 34 described above is rotatably supported by a bearing portion 35. The bearing portion 35 is a bearing that is provided in contact with the bearing bodies 120a, 120b, and 120c that rotatably support the rotating shaft 34, the bracket 121 that supports the bearing bodies 120a to 120c, and the second rotating shaft portion 52. Carrier 122.

  The bracket 121 is hollow, has a first partition wall 123 at one axial end portion 121A, and has a second partition wall 124 at an intermediate portion in the axial direction. One end 121 </ b> A in the axial direction of the bracket 121 and the other end 84 </ b> B in the axial direction of the casing 41 are abutted and fixed to each other detachably by the bracket bolt 126.

  A space 127 </ b> A that opens to the outside is formed between the first partition wall 123 and the second partition wall 124. An insertion hole 128 is formed in the first partition wall 123. An insertion hole 129 is formed in the second partition wall 124. A space 127 </ b> B is formed on the other side of the second partition wall 124 in the direction of the rotation axis 33.

  Bearing bodies 120 a and 120 b are attached to the belling carrier 122. A bearing body 120 c is mounted on the fourth rotating shaft portion 54, and the outer ring bodies 130 a to 130 c of these bearing bodies 120 a to 120 c are fixed to the bracket 121. The inner ring bodies 131 a and 131 b of the bearing bodies 120 a and 120 b are fixed to the belling carrier 122 by nuts 133 through washers 132. The bearing bodies 120a and 120b are realized by, for example, angular ball bearings, but may be realized by other bearings. The bearing body 120c is realized by, for example, a radial bearing, but may be realized by another bearing.

  A bearing lid body 135 that protects the bearing body 120a is detachably fixed to the opening end of the other end 121B in the axial direction of the bracket 121 by a mounting bolt 136. One end of the bearing lid 135 in the axial direction is in contact with the outer ring body 130a of the bearing body 120a. This prevents the bearing bodies 120a to 120c from moving in the axial direction.

  An opening is formed in the center portion of the bearing lid body 135. The first rotating shaft portion 51 of the rotating shaft 34 protrudes outside the bracket 121 through the opening. The other end in the axial direction of the first rotating shaft 51 is attached to a rotation driving source (not shown) such as an electric motor in a state in which the first rotating shaft 51 is mutually prevented by a key.

  The stuffing box portion 88 is formed so that the inner diameter is larger than the outer diameter of the first shaft portion 61 of the rotor 38. The outer peripheral surface of the stuffing box portion 88 protrudes into the space 127 </ b> A through the insertion hole 128 of the first partition wall 123 of the bracket 121. The outer peripheral surface is in contact with the first partition wall 123.

  The first shaft portion 61 of the rotor 38 is inserted into the stuffing box 88. In addition, an annular storage space 200 centered on the rotation axis 33 is formed between the stuffing box 88 and the first shaft portion 61, and the seal portion 44 is fitted into the storage space 200.

  The oil seal 110 has an annular shape, and an outer peripheral surface thereof is attached to an insertion hole 129 provided in the second partition wall 124, and an inner peripheral surface thereof is inserted into the insertion hole 129. It slides in contact with the portion 54. The oil seal 110 prevents the lubricating oil of the bearing body 120 disposed on the other side in the axial direction from the second partition wall 124 from leaking to the one side in the axial direction.

  Further, an annular drain plate may be provided on the fourth rotating shaft portion 54 on one side in the axial direction of the second partition wall 124. By providing the draining plate, for example, a liquid such as water is prevented from coming into direct contact with the oil seal 110, and deterioration of the oil seal 110 can be prevented.

  When the vane pump 31 as described above is started, that is, when the rotary shaft 34 is rotationally driven by a rotational drive source (not shown), the rotor 38 rotates. When the rotor 38 rotates, the three vanes 39A, 39B, and 39C move in the radial direction of the rotor 38 through the vane grooves 37, respectively, and both radial end portions 70A, 70B, and 70C are accommodated in the housing space 40 of the casing 41. It rotates in contact with the inner peripheral surface 80 of the casing 41 and applies an extrusion force to the transferred material in the transfer path.

  When the transferred material is introduced from the supply hole 82 </ b> A, the transferred material is taken into the pump chamber 81. When the rotor 38 rotates in the rotation direction A, the transferred material is transferred from the supply hole 82A to the discharge hole 82B.

  In the above embodiment, the case where three vanes 39 are provided has been described. However, the present invention is not limited to this, and a configuration in which four or more vanes are provided may be used. In this case, the number of vane grooves according to the number of vanes may be formed in the rotor.

  In another embodiment of the present invention, the seal portion 44 may employ not only a mechanical seal structure but also a gland packing seal structure.

  According to the present embodiment, when one vane is disposed at the inflection point P1 on the upstream side of the first inner peripheral surface 20, another second vane adjacent to the downstream side in the rotational direction A from this vane. Is arranged upstream of the inflection point P3 between the first inner peripheral surface 20 and the fourth inner peripheral surface 23 in the rotational direction A. Therefore, during the period until the second vane reaches the inflection point P3 between the first inner peripheral surface 20 and the fourth inner peripheral surface 23, the two vanes are in sliding contact with the first inner peripheral surface 20. The transfer path between the supply hole 82A and the discharge hole 82B can be blocked with high liquid tightness.

  Thereby, the leakage of the transferred material due to the differential pressure between the pressure of the transferred material in the discharge hole 82B and the pressure of the transferred material in the supply hole 82A during operation of the vane pump 31 can be reduced. Quantitative stability can be improved.

DESCRIPTION OF SYMBOLS 20 1st internal peripheral surface 21 2nd internal peripheral surface 22 3rd internal peripheral surface 23 4th internal peripheral surface 31 Vane pump 32 Cover body 33 Rotating axis 34 Rotating shaft 35 Bearing part 37 Vane groove 38 Rotor 39A, 39B, 39C Vane 40 Housing space 41 Casing 44 Sealing part 61 First shaft part 62 Second shaft part 63 Rotor body 80 Inner peripheral surface 81a, 81b, 81c, 81d, 81e, 81f Pump chamber 82A Supply hole 82B Discharge hole 88 Stuffing box part

Claims (1)

Three or more vane grooves (37) that are driven to rotate in a predetermined rotation direction (A) around the rotation axis (33), have a right cylindrical outer peripheral surface, and are orthogonal to the rotation axis (33) are formed radially. A rotor (38) to be operated;
Three or more vanes (39) that are movably fitted along the vane grooves (37) in the vane grooves (37) of the rotor (38);
The first to fourth inner peripheral surfaces (20, 21) having an accommodating space (40) in which the rotor (38) and the vanes (39) are accommodated and having different radii every 90 ° with respect to the rotation axis (33). , 22, 23) includes a casing (41) formed facing the housing space (40),
The first inner peripheral surface (20) is composed of a part of a right cylindrical surface having a predetermined first radius (R1) centered on the rotation axis (33),
The second inner peripheral surface (21) is opposite to the first inner peripheral surface (20) with respect to the rotation axis (33), is smaller than the first radius (R1), and is A sum of one radius (R1) and a portion of a (R2) right cylindrical surface of a second radius equal to the length of each vane (39);
The third inner peripheral surface (22) has an end on the upstream side in the rotational direction (A) of the first inner peripheral surface (20) and a downstream side in the rotational direction (A) of the second inner peripheral surface (21). The boundary position (P2) between the third inner peripheral surface (22) and the second inner peripheral surface (21) and the first inner peripheral surface (20) and the third inner peripheral surface (22). Consists of a curved surface connecting the boundary position (P1) and protruding radially outward,
The fourth inner peripheral surface (23) includes an end on the downstream side in the rotational direction (A) of the first inner peripheral surface (20) and the upstream side in the rotational direction (A) of the second inner peripheral surface (21). The boundary position (P3) between the first inner peripheral surface (20) and the fourth inner peripheral surface (23), the fourth inner peripheral surface (23), and the second inner peripheral surface (21). Consisting of a curved surface connecting the boundary position (P4) of FIG.
The casing (41) opens on the third inner peripheral surface (22) and opens on the supply hole (82A) to which the transferred product is supplied and on the fourth inner peripheral surface (23). A vane pump comprising a discharge hole (82B) for discharging.

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