JP2005299494A - Stator for uniaxial eccentric screw pump - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a stator for a uniaxial eccentric screw pump easy to manufacture as compared with a conventional general stator, enable to reduce cost and weight, and to easily manufacture a large size stator. <P>SOLUTION: A metal stator having a female screw hole having an elongated circle section opening and penetrating through in a longitudinal direction at a center part. A plurality of plate shape body 6 cut in a direction perpendicularly crossing a center axle line s with a fixed thickness and having female screw hole part 7a formed thereon are connected in a series. The female screw hole part 7a of each plate shape body 6 is formed three-dimensionally. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a stator in which a main body portion of a uniaxial eccentric screw pump is configured together with a male screw rotor.

  The stator of this type of pump is generally composed of two types, rubber and metal.

  In the case of a rubber stator, the rubber material is injected into the mold and vulcanized, but the form of the female screw hole for inserting and rotating the rotor is complicated, and it takes days and costs to manufacture the mold. Yes.

  In the case of a metal stator, a cast product takes days and costs to manufacture a mold in the same manner as a rubber stator. Machined products, on the other hand, form a female threaded hole from a metal round bar material by electrical discharge machining or cutting, but the machining is difficult, and an expensive and special processing machine such as a three-dimensional laser must be used. It requires skill to operate, and mass production is difficult and expensive. In addition, the stator is very heavy and inconvenient to handle, and it is particularly difficult to manufacture a large-sized stator.

Therefore, for example, a stator is proposed in which a number of thin metal plates having the same oval opening are laminated by aligning the central axis of each opening and the opening direction is sequentially shifted by a small angle to form a stepped female screw hole. (See Patent Document 1).
Japanese Utility Model Publication No. 63-65883 (Examples, FIGS. 1 to 3)

  However, the stator described in the above publication has the following disadvantages. That is, since there is a stepped step on the inner peripheral surface of the female screw hole, it is difficult to use the inner peripheral surface without applying a rubber lining or the like. Also, since the thickness of the metal plate is very thin at about 0.25 mm, it is necessary to manufacture a huge number of metal plates of hundreds even with a small stator, and to stack them by sequentially shifting a minute angle. It takes time and effort.

  The present invention has been made in view of the above points, and is uniaxial eccentric screw that is easier to manufacture than the above-described conventional general stator, can reduce cost, can reduce weight, and can easily manufacture a large size. It aims at providing the stator for pumps.

  In order to achieve the above object, a uniaxial eccentric screw pump stator according to the present invention is formed by cutting a metal stator having an oval cross-sectional shape with a female screw hole penetrating in the longitudinal direction in the center in a direction perpendicular to the central axis A plurality of circular plate-like bodies having a fixed thickness and a female screw hole portion formed three-dimensionally (three-dimensionally) in the central portion are joined and integrated in series.

According to the stator for a uniaxial eccentric screw pump having the above-described configuration, a metal plate-like body having the same form is manufactured in advance, and a die that configures the inner diameter portion in a required number according to the length of the stator. It can be easily manufactured by covering the child and joining them in series and integrating them by welding or the like. In addition, since a female screw hole part that constitutes a part of the female screw hole of the stator is usually machined by a three-dimensional laser or a lathe at the center of a circular metal plate having a thickness of several millimeters, a conventional metal round bar can be used as a female screw. Manufacture is easier than forming holes, and a plurality of types of plate-like bodies having different inner diameters (sizes) can be easily manufactured. For this reason, the cost can be greatly reduced, and various types of stators having different sizes and inner diameters can be manufactured in a short period of time.

  As described in claim 2, the plate-like bodies are joined with an adhesive or an adhesive film sheet interposed between the respective plate-like bodies, and are inserted into a cylindrical outer cylinder (metal casing). can do.

  According to the stator for a uniaxial eccentric screw pump according to claim 2, liquid leakage from the inner peripheral surface of the female screw hole to which high pressure acts during pump operation can be surely prevented, and the plate-like body can be easily integrated. is there. Furthermore, since the stator main body in which a plurality of plate-like bodies are integrated is inserted into the outer cylinder, the overall strength is improved and the durability is increased.

  As described in claim 3, spirally continuous openings can be provided on both sides of the straight portion of the female screw hole portion of each plate-like body (in a state where the plate-like bodies are joined in series).

  According to the stator for the uniaxial eccentric screw pump according to the third aspect, the weight of the stator is reduced and the weight is reduced by providing the openings on both sides of the female screw hole portion.

  As described in claim 4, a rubber lining can be applied along the inner peripheral surface of the female screw hole formed by the female screw hole portion of each plate-like body.

  According to the stator for the uniaxial eccentric screw pump according to the fourth aspect, liquid leakage from between the plate-like bodies can be prevented by covering the inner peripheral surface of the female screw hole with the rubber lining.

  As described in claim 5, the spiral openings on both sides of the female screw hole can be used as a flow path (jacket) for hot water or cold water.

  According to the stator for a uniaxial eccentric screw pump according to claim 5, by using each opening as a heating jacket or a cooling jacket, an object to be conveyed conveyed by the uniaxial eccentric screw pump is maintained at an optimum temperature while being heated or cooled. Can do.

  Since the stator for a uniaxial eccentric screw pump according to the present invention has the above-described configuration, a plurality of types of metal plate-like bodies are manufactured in advance, and the type is determined according to the size of the stator and the required number of plate-like shapes. By joining the bodies in series and integrating them by welding or the like, an arbitrary stator can be easily manufactured. Normally, one of the female screw holes of the stator is formed at the center of a circular metal plate having a thickness of several millimeters. Since it is only necessary to produce a plate-like body of a desired form by processing the female screw hole part constituting the part with a three-dimensional laser or a lathe, it is manufactured compared to forming a female screw hole from a conventional metal round bar. Easy. Therefore, the cost can be greatly reduced as compared with the conventional case, and various types of stators having different sizes and inner diameters can be easily manufactured in a short period of time, and the weight can be reduced.

  Embodiments of a uniaxial eccentric screw pump stator according to the present invention will be described below with reference to the drawings.

  FIG. 1 is a longitudinal sectional view showing a uniaxial eccentric screw pump provided with a stator according to an embodiment of the present invention, FIG. 2 is an enlarged longitudinal sectional view showing the stator of FIG. 1, and FIG. 3 is a single sheet constituting the stator. It is the front view and perspective view which show a metal plate (metal plate-shaped object).

As shown in FIG. 1, a pump body portion 2 of a uniaxial eccentric screw pump 1 includes a male screw rotor 3 having a true circular cross section and a female screw hole 7 having an oval cross section having an opening cross section having a pitch twice that of the rotor 3. 2, the rotor 3 rotates eccentrically within the female screw hole 7 by a distance e around its central axis s. The rotor 3 revolves in the female screw hole 7 while revolving in one direction in the direction opposite to the rotation around the central axis s, and the rotor 3 rotates in the cross section at an arbitrary position of the female screw hole 7 while the oval opening 7b. It is restrained by the straight portions 7c and 7c and reciprocates in the long axis direction.

  The rotor 3 includes a drive shaft 11 connected to an electric motor (not shown), and a coupling rod 13 connected to one end of the drive shaft 11 via a universal joint 12. One end of the rotor 3 is connected via the universal joint 14. An endstat 15 is attached to the stator 5 on the other end side of the rotor 3 to serve as a discharge port or a suction port. On the other hand, the opposite end of the stator 5 is connected to a pump casing 16, and a flanged opening 16 a that serves as a suction port or a discharge port projects upward at an intermediate position in the longitudinal direction of the pump casing 16. The drive shaft 11 is rotatably supported in the bearing unit 17 via a bearing 17a, and a mechanical seal 18 is mounted around the drive shaft 11 on the pump casing 16 side of the bearing unit 17. Although these configurations are known, the stator 5 which is a characteristic part of the present invention will be described in detail.

  As shown in FIG. 2, the stator 5 has a structure in which a metal circular plate-like body 6 is joined in series and fitted into a cylindrical metal casing (outer cylinder) 8. The plate-like body 6 has the same form, and a female screw hole 7a is formed at the center thereof. In this example, each plate-like body 6 is formed by three-dimensional lasering a female screw hole 7a three-dimensionally at the center of a circular plate-like body 6 having a constant thickness (several millimeters) such as a stainless steel plate. As shown in FIG. 3, the female screw hole portion 7a is an oval opening 7b as viewed from the front, and is formed so as to be slightly twisted in a clockwise direction from the front to the rear. A predetermined number (several tens) of female screw holes 7a of a plate-like body 6 are loosely inserted into a core, which is a mold having an inner diameter shape, and joined to each other to form a stator body 5 '. The periphery of the joint portion of the body 6 is integrally formed by welding by TIG welding or the like. A core (not shown) is inserted into the female screw hole 7 of the stator body 5 ′ thus manufactured, and unvulcanized rubber is injected into the gap between the core and the inner peripheral surface of the female screw hole 7 and vulcanized. A rubber lining 9 can be applied. On the other hand, when such a rubber lining 9 is not applied, an adhesive film sheet (not shown) is interposed between the plate-like bodies 6 so as to be integrally joined to prevent liquid leakage. it can. An adhesive may be used instead of the adhesive film sheet.

  The stator body 5 ′ thus manufactured is loaded into a cylindrical metal casing 8 to become a stator 5 as a final product.

  FIG. 4 is a perspective view showing a metal plate-like body constituting a stator according to another embodiment of the present invention.

  As shown in FIG. 4, in the plate-like body 6 ′ of the present example, an elliptical cross section is formed on both sides of the straight portion 7c of the oval opening 7b (see FIGS. 2B and 3A) of the female screw hole portion 7a. Alternatively, the opening 10 having a circular cross section is formed so as to be slightly twisted in a clockwise direction from the front surface to the rear surface. For this reason, circular openings 10 are formed in a spiral shape on both sides in parallel with the female screw hole 7 in a state where the plate-like bodies 6 ′ are joined in series to form the stator body 5 ′. Therefore, the weight is reduced as compared with the stator 5 of the above embodiment, and hot water is circulated through the flow passage in which each opening 10 is spirally connected to be used as a heating jacket, or conversely, cold water is circulated. Can be used as a cooling jacket. Since other configurations are the same as those of the stator 5 of the above-described embodiment, detailed description is omitted, and common members are illustrated using the same reference numerals.

It is a longitudinal cross-sectional view which shows the uniaxial eccentric screw pump provided with the stator concerning the Example of this invention. 2A is an enlarged longitudinal sectional view showing the stator of FIG. 1, and FIG. 2B is a transverse sectional view for explaining the relationship between the stator and the rotor. FIG. 3A is a front view showing one metal plate (metal plate-like body) constituting the stator of FIG. 1, and FIG. 3B is a perspective view thereof. It is a perspective view which shows the metal plate-shaped body which comprises the stator concerning the other Example of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Uniaxial eccentric screw pump 2 Pump main-body part 3 Male thread type rotor 5 Stator 5 'stator main body 6 Metal plate-shaped body (metal plate)
7 Female threaded hole 7a Female threaded hole 7b Oval opening 8 Metal casing (outer cylinder)
9 Rubber Lining 10 Circular Opening 11 Drive Shaft 12/14 Universal Joint 13 Coupling Rod 15 Endstat 16 Pump Casing 16a Flange Opening 17 Bearing Unit 17a Bearing 18 Mechanical Seal

Claims (5)

A plurality of metal stators having an oval opening cross section with a female screw hole penetrating in the longitudinal direction in the central part and three-dimensionally forming the female screw hole part in the central part with a constant thickness cut in a direction perpendicular to the central axis A stator for a uniaxial eccentric screw pump, characterized in that it is constructed by joining and integrating a series of circular plate-like bodies. The stator for a uniaxial eccentric screw pump according to claim 1, wherein a plate-like body is joined with an adhesive or an adhesive film sheet interposed between the plate-like bodies, and is fitted into a cylindrical outer cylinder. The uniaxial eccentric screw pump stator according to claim 1 or 2, wherein spirally continuous openings are provided on both sides of the straight portion of the female screw hole portion of each plate-like body. The stator for a uniaxial eccentric screw pump according to any one of claims 1 to 3, wherein a rubber lining is provided along an inner peripheral surface of the female screw hole formed by the female screw hole portion of each plate-like body. The stator for a uniaxial eccentric screw pump according to claim 3, wherein the spiral openings on both sides of the female screw hole are used as a flow path for hot water or cold water.

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