JP2008082218A - Rotary pump - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To facilitate replacement of a rotary shaft and reduce replacement cost. <P>SOLUTION: The rotary pump 1 is provided with a pump casing 2 including a cylindrical pump chamber P, a rotor 3 provided with corrugated blades 32 of which axial position periodically changes along a circumference direction and stored in the pump chamber P with keeping circumference edges and an apexes of the corrugated blades 32 contact and slide on a circumference surface and both end surfaces of each pump chamber P, a bearing 51 supporting the rotary shaft 7 connected to a rotor 3 on the pump casing 2, and a seal member 84 sealing the rotary shaft 7 between the bearing 51 and the rotor 3. The rotary shaft 7 is divided and fastened by screws between the bearing 51 and the seal member 84. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a rotary pump mainly used for pumping a slurry-like fluid mixed with powder.

This type of rotary pump includes a pump casing having a cylindrical pump chamber, and a rotor having corrugated blades whose axial position changes periodically along the circumferential direction. Slidably contact the peripheral surface and both end surfaces of the pump chamber, the rotor accommodated in the pump chamber, the supply / discharge path provided in the pump casing to open to the peripheral surface of the pump chamber, and the corrugated blade to engage the gate. There is known a device including a gate mechanism that shuts off between the supply and discharge passages and reciprocates the gate in the axial direction as the rotor rotates (Patent Document 1).
JP 2002-37456 A

  In this rotary pump, the rotor is connected to one end of the rotary shaft, and the other end of the rotary shaft is supported on the pump casing via a bearing. Further, in order to prevent the liquid leaking from the pump chamber from reaching the bearing, a seal member is provided between the bearing and the rotor to seal the rotating shaft.

  By the way, when the liquid leaked from the pump chamber contains an organic solvent, it is necessary to use a seal member made of a fluororesin (PTFE or the like) that does not swell or dissolve. In some cases, fine solid particles are contained in the liquid. In either case, the rotating shaft is worn by frictional contact with the seal member. When the wear has progressed to some extent, the rotating shaft must be replaced with a new one. However, since a bearing is provided at the other end of the rotating shaft, the bearing must be removed and attached when replacing the rotating shaft, which is cumbersome. In addition, although only a part of the rotating shaft is worn, the entire rotating shaft must be replaced, which is problematic in terms of cost.

  In view of such circumstances, an object of the present invention is to provide a rotary pump in which the rotation shaft can be easily replaced and the replacement cost can be reduced.

  The present invention for solving the above problems is a rotor having a pump casing having a cylindrical pump chamber, and a corrugated blade whose axial position changes periodically along the circumferential direction. A rotor housed in the pump chamber with its peripheral edge and apex slidably contacted with the peripheral surface and both end surfaces of the pump chamber, a bearing that supports the rotary shaft connected to the rotor on the pump casing, and rotation between the bearing and the rotor A seal member that seals the shaft, a supply / discharge path provided in the pump casing to open to the peripheral surface of the pump chamber, and a gate is engaged with the corrugated blades to block between the supply / discharge paths, and the rotor rotates. In the rotary pump having a gate mechanism for reciprocating the gate in the axial direction, the rotary shaft is divided between the bearing and the seal member, and the divided rotary shafts are detachably coupled. To.

  One of the divided rotary shafts forms a small-diameter male screw portion, the other forms a stepped hole having a female screw portion, and guides one rotary shaft with the stepped hole of the other rotary shaft. The male screw portion is preferably screwed into the female screw portion.

  The portion of the pump casing facing the pump chamber is configured with a detachable lid, the rotor is fastened and fixed to the tip of the rotating shaft with a nut member, and the guide portion for fitting the circumferential portion of the nut member is the inner surface of the lid It is preferable to provide in.

  According to the present invention, when the rotating shaft is replaced, the worn portion is removed from the portion supported by the bearing, and a new one can be attached. Become.

  Further, only the worn part of the rotating shaft needs to be replaced, which is advantageous in terms of cost.

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.
FIG. 1 is a cross-sectional view of a rotary pump according to the present invention, and FIG. 2 is a cross-sectional view taken along line AA of FIG.
The rotary pump 1 includes a pump casing 2 having a cylindrical pump chamber P and a rotor 3 accommodated in the pump chamber P.

  The pump casing 2 is composed of a bottomed cylindrical casing body 21 and a lid 22 in which a portion facing the pump chamber P of the casing body 21 is detachable, and the lid 22 is attached to the end of the casing body 21. By fastening with the bolt 23, the pump chamber P which is a substantially cylindrical hollow part is formed inside. The casing body 21 includes a supply path 24 that opens to the peripheral surface P3 of the pump chamber P and supplies liquid to the pump chamber P, and a discharge that opens to the peripheral surface P3 of the pump chamber P and discharges liquid from the pump chamber P. A passage 25 is formed (see FIG. 2). The supply passage 24 and the discharge passage 25 are formed in a circular cross section, and the inner diameter thereof is formed smaller than the height of the peripheral surface P3 of the pump chamber P. Further, between the connection portion of the supply passage 24 and the connection portion of the discharge passage 25 of the pump casing 2, a long gate chamber G is provided in a direction orthogonal to the upper and lower end faces P <b> 1 and P <b> 2 of the pump chamber P. .

  As shown in FIG. 3, the rotor 3 includes a hub portion 31 through which the rotary shaft 7 is inserted, and extends from the hub portion 31 by the same length radially outward over the entire circumference, and the axial position is continuously with the phase. And a corrugated wing 32 that changes. The corrugated blade 32 has a complete cycle having two convex top portions 32a having the highest axial height and two concave top portions 32b having the lowest height (see FIG. 6). A center hole 33 for inserting a rotating shaft 7 to be described later is formed at the center of the hub portion 31.

  The upper and lower end faces P <b> 1 and P <b> 2 of the pump chamber P are formed so that the convex apex portions 32 a and the concave apex portions 32 b of the corrugated blades 32 of the rotor 3 are in sliding contact with each other. The peripheral surface P3 of the pump chamber P is formed so that the peripheral edge 32e of the corrugated blade 32 is in sliding contact.

  A gate mechanism 4 is provided between the supply path 24 and the discharge path 25 to block the space on the supply path 24 side and the space on the discharge path 25 side defined by the corrugated blades 32 (see FIG. 6). . The gate mechanism 4 includes a gate 41 and a gate guide 42 that guides the gate 41. As shown in FIG. 4, the gate 41 is provided with a notch 41 a that engages with the corrugated blade 32 of the rotor 3 at the lower center of the rectangular plate member. The gate guide 42 is formed in a substantially quadrangular prism-shaped member that is hermetically fitted into the gate chamber G, a groove-shaped guide portion 42 a (axial direction) for guiding the gate 41 in the axial direction, and the supply passage 24 side of the pump chamber P. And a communication portion 42b (circumferential direction) for communicating with the discharge passage 25 side.

  The notch 41 a of the gate 41 engages with the corrugated blade 32 of the rotor 3, and hermetically contacts both the front and back surfaces of the corrugated blade 32 and the peripheral edge 32 e, and the axial position of the corrugated blade 32 is displaced by the rotation of the rotor 3. Accordingly, the gate 41 is guided by the guide portion 42a of the gate guide 42 and reciprocates in the axial direction. Thereby, since the gate 41 always blocks | interrupts the communication part 42b of the gate guide 42, the space by the side of the supply path 24 of the pump chamber P and the space by the side of the discharge path 25 are interrupted | blocked.

  The pump casing 2 includes a cylindrical shaft box portion 5 at the end of the casing body 21, and is installed on a floor plate or the like via a mounting plate 6 fastened to the shaft box portion 5 with bolts 61. A bearing 51 is provided inside the shaft box portion 5 to support the rotating shaft 7 of the rotor 3. Specifically, a bearing 51 is fitted into the shaft box portion 5, and a nut 52 is screwed onto the rotating shaft 7 to be fastened and fixed to an inner member of the bearing 51. The axle box portion 5 is fixed to the casing body 21 with bolts 61.

  The rotary shaft 7 has its tip end spline-coupled to the hub portion 31 of the rotor 3, and a nut member 81 is screwed onto the male screw portion 7 a at its tip to fix the rotor 3. Further, a ring-shaped guide member 82 is fixed to the inner surface of the lid 22 and the circumferential portion 81a of the nut member 81 is fitted. The rotating shaft 7 is driven by a motor (not shown).

The casing main body 21 is fixed with a sleeve 83 through which the rotary shaft 7 is inserted, and a seal member 84 is disposed therein to seal the rotary shaft 7. This prevents the liquid leaking from the pump chamber P from reaching the bearing 51.
By the way, the rotating shaft 7 is divided between the bearing 51 and the seal member 84 and screwed. That is, the split shaft 70 on the seal member 84 side forms a small-diameter male screw portion 70a on the split surface, while the split shaft 71 on the bearing 51 side forms a stepped hole 71b having the female screw portion 71a on the split surface. is there. The male screw portion 70a is screwed into the female screw portion 71a while the split shaft 70 is guided by the stepped hole 71b of the split shaft 71.

Next, the operation of the rotary pump 1 will be described.
When the rotating shaft 7 rotates (counterclockwise in FIG. 2) by driving a motor (not shown), the rotor 3 connected to the rotating shaft 7 rotates in the pump chamber P. Simultaneously with the start of the rotation, the liquid is supplied to the supply path 24, and the pocket space of the rotor 3, that is, the corrugated blade surface 32 c between the two convex top portions 32 a of the rotor 3 and the upper end surface of the pump chamber P. The space surrounded by P1 and the space surrounded by the corrugated blade back surface 32d between the two concave top portions 32b of the rotor 3 and the lower end surface P2 of the pump chamber C are filled with liquid. The liquid thus filled is transferred to the discharge path 25 side through the pump chamber P by the rotation of the rotor 3. FIG. 6 is a diagram schematically showing the corrugated blades 32, the supply passage 24, the discharge passage 25, the pump chamber P, and the gate 41 of the rotor 3. Originally cylindrical and circular portions are developed on a plane, The operation is easy to understand.

  By the way, since the rotating shaft 7 is worn by frictional contact with the seal member 84, the rotating shaft 7 must be replaced with a new one when the wear has progressed to some extent. Since the rotary shaft 7 is divided and screwed between the bearing 51 and the seal member 84 as described above, only the worn portion 70 on the bearing 51 side needs to be replaced with a new one. .

  That is, the lid 22 is removed from the casing body 21, the nut member 81 at the tip of the rotating shaft 7 is removed, and the bolt 61 is loosened to release the coupling between the casing body 21 and the axle box portion 5. Thereafter, the corrugated blade 32 may be removed from the rotary shaft 7, the split shaft 70 may be removed from the split shaft 71, and a new split shaft 70 may be attached to the split shaft 71. That is, since the split shaft 71 on the bearing 51 side that is not worn does not have to be removed from the axle box portion 5, the labor of attaching and detaching the bearing 51 to and from the casing body 21 is saved, and the work is facilitated. In addition, since only the worn split shaft 70 on the seal member 84 side needs to be replaced, it is advantageous in terms of cost.

  Further, when the split shafts 70 and 71 are coupled, the male screw portion 70a is screwed into the female screw portion 71a while guiding the split shaft 70 through the stepped hole 71b of the split shaft 71. Ensuring the necessary concentricity becomes easy.

  In addition, since the guide member 82 is fixed to the lid 22 to support the tip of the rotating shaft 7, even when a non-uniform load is applied to the rotor 3 due to the occurrence of cavitation, the bending of the rotating shaft 7 causes the guide member 82 to bend. Therefore, the rotor 3 is not pressed against the pump housing 2 and the corrugated blades 32 can be prevented from being worn or damaged.

By the way, in order to prevent wear of the rotating shaft 7 due to frictional contact with the seal member 84, a collar may be attached to the rotating shaft 7, but in this case, the following problems occur.
That is, in order to ensure the rigidity required for the rotating shaft 7, only the collar mounting portion of the rotating shaft 7 cannot be reduced in diameter, so the diameter of the rotating shaft 7 is effectively increased by the thickness of the collar. Now, if the size of the pump housing 2 is to be kept constant, the diameter of the corrugated blade 32 must also be kept constant, and the effective diameter of the corrugated blade 32 becomes smaller by the increase in the diameter of the rotating shaft 7. The discharge amount per rotation of the rotor 3 is reduced. Here, in order to secure the same amount of discharge as before, since it is necessary to increase the rotational speed of the corrugated blade 32, not only cavitation is likely to occur, but also the wear of the seal member 84 becomes severe.

  In addition, this invention is not limited to the thing of the above embodiment, It can change variously as needed.

Sectional drawing of the rotary pump of this invention. AA sectional view taken on the line AA of FIG. (A) is sectional drawing of a rotor, (b) is a side view of a rotor. (A) is a side view of the gate, (b) is a plan view of the gate, and (c) is a front view of the gate. (A) is a side view of a gate guide, (b) is a front view of a gate. The figure explaining the pump action of a corrugated blade.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Rotating pump 2 Pump housing 3 Rotor 4 Gate mechanism 5 Shaft box part 7 Rotating shaft 21 Casing main body 22 Lid 32 Corrugated blade 32a Convex top part 32b Concave top part 32e Peripheral 41 Gate 42 Gate guide 51 Bearing 52 Nut 70 Split shaft 70a Male screw part 71 Split shaft 71a Female thread portion 71b Stepped hole 81 Nut member 81a Circumferential portion 82 Guide member 83 Sleeve 84 Seal member P Pump chamber G Gate chamber

Claims (3)

  A rotor having a pump casing having a cylindrical pump chamber, and a corrugated blade whose axial position changes periodically along the circumferential direction, the peripheral edge and the apex of the corrugated blade being respectively the peripheral surface of the pump chamber A rotor housed in a pump chamber in sliding contact with both end faces, a bearing for supporting a rotating shaft connected to the rotor on a pump casing, a seal member for sealing the rotating shaft between the bearing and the rotor, and a pump chamber A gate mechanism for reciprocating the gate in the axial direction as the rotor rotates by engaging the gate with the corrugated blades to shut the gap between the supply / discharge path provided in the pump casing to open to the peripheral surface A rotary pump comprising: a rotary pump having a rotary shaft divided between a bearing and a seal member, and the divided rotary shafts being detachably coupled.   One of the divided rotary shafts forms a small-diameter male screw portion, the other forms a stepped hole having a female screw portion, and guides one rotary shaft with the stepped hole of the other rotary shaft. The rotary pump according to claim 1, wherein the male screw portion is screwed into the female screw portion.   The portion of the pump casing facing the pump chamber is configured with a detachable lid, the rotor is fastened and fixed to the tip of the rotating shaft with a nut member, and the guide portion for fitting the circumferential portion of the nut member is the inner surface of the lid The rotary pump according to claim 2, wherein the rotary pump is provided.

Images