JP2007303412A - Uniaxial eccentric screw-pump - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a uniaxial eccentric screw-pump capable of solving various problems caused by an intermediate rotating shaft such as swinging rotation by the intermediate rotating shaft or fretting corrosion by eliminating the intermediate rotating shaft which was conventionally essential or customarily essential for disassembly work of a shaft seal part, and capable of achieving reduction of length of a pump, simplification of a structure, reduction of the weight and miniaturization. <P>SOLUTION: In the uniaxial eccentric screw-pump, a male screw shaped rotor 5 connected to a driving shaft 7 of a driving motor 6 disposed on an end of a motor bracket 15 connected to a pump casing 2 through a connecting rod 12 and universal joints 9 and 14 is rotatably fitted into a female screw shaped stator 3a to be eccentrically rotated, and an object to be carried is carried. The driving shaft 7 of the driving motor 6 is inserted into the pump casing 2 from an end opening 2a of the motor bracket 15, an outer peripheral surface of a driving shaft insertion part 7a is sealed by a mechanical seal 8, and a joint head part 9 is directly attached to the driving shaft end 7a, and is connected to an end of the connecting rod 12. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention conveys various foods such as milk, soy milk, jam, dressing, surimi, tomato paste, grilled meat sauce, liquid chemicals, solid-containing liquids, slurries, high viscosity liquids, etc. In particular, the present invention relates to a structure in which a drive shaft of a drive motor and a male screw rotor are connected via a connecting rod and a universal joint.

  As shown in FIG. 2, this type of single-shaft eccentric screw pump 30 is connected to a drive motor 32 via a pump casing 31 and a motor bracket 37 as is well known, and the rotational drive unit is driven by the drive motor 32. A male threaded rotor in which the end of the shaft 32a is inserted into the proximal end side cylindrical portion 33b of the drive shaft 33 integrally provided with the intermediate rotation shaft 33a and is connected to the tip of the drive shaft 33 via a metal connecting rod 34 ( 1 has a structure in which an object to be conveyed is conveyed by being rotatably inserted into an internally threaded stator (see numeral 3 in FIG. 1) and rotating eccentrically. In the past, the gland packing 36 was used to seal the shaft around the drive shaft tip portion 33c. However, since this gland packing 36 is heavily worn and requires constant disassembly work, an intermediate rotating shaft 33a is provided. ing. Further, since the intermediate rotating shaft 33a is interposed, the opening 37a for maintaining the gland packing 36 in the motor bracket 37 has been a problem from the viewpoint of PL.

As a prior art, a uniaxial eccentric screw pump using a gland packing similar to the above for shaft sealing is described (for example, refer to the prior art in Patent Document 1). Since the drive shaft 33 of the drive motor (usually an electric motor) rotates about the center axis of the drive motor, it is necessary to absorb the amount of eccentricity with the eccentric rotating rotor, as shown in FIG. In addition, through holes 34a are formed in both ends of the metal connecting rod 34 so as to taper outward from the central shaft portion, and are connected to the tip of the rotor and the drive shaft 33 by pins 34b. The periphery is attached by a sleeve 34c and a retaining ring 34d, and is connected to each other so as to be bent in all directions within a certain range.
JP-A-9-264264 (background art and FIG. 10)

  -Since a uniaxial eccentric screw pump normally requires an eccentric motion with a male screw rotor, there is a specific disadvantage that a large radial load is generated by a differential pressure, a high-speed rotational motion, or the like.

  In the uniaxial eccentric screw pump provided with the intermediate rotation shaft at the tip end side of the drive shaft described above, the intermediate rotation shaft 33a is provided between the drive shaft end and the universal joint as shown in FIG. The overhang length to the pump casing side becomes longer. For this reason, in combination with the radial load generated in the universal joint part, there is also an influence due to looseness of fitting, etc., and as a result of a large bending moment acting on the swing of the intermediate rotating shaft 33a and the drive shaft bearing, the pump casing shaft There is a problem that liquid leakage is likely to occur from the sealing portion 36 or the drive shaft shaft sealing portion, or fretting corrosion occurs at the fitting portion 33b between the end of the drive shaft 32a and the intermediate rotation shaft 33a.

  -Furthermore, there exists a problem that the full length of a pump becomes long by presence of the intermediate | middle rotating shaft 33a.

  The present invention has been made in view of the above-described points, and by eliminating the intermediate rotation shaft that has been conventionally or conventionally essential for disassembling the shaft seal portion, various inventions resulting from the above-described intermediate rotation shaft are provided. It is an object of the present invention to provide a single-shaft eccentric screw pump that eliminates problems such as the occurrence of swinging and fretting corrosion caused by an intermediate rotating shaft, and shortening the overall pump length, simplifying the structure, reducing the weight, and reducing the size.

  In order to achieve the above object, a uniaxial eccentric screw pump according to the present invention includes a male screw rotor connected to a drive shaft of a drive motor provided at one end of a motor bracket connected to a pump casing via a connecting rod and a universal joint. Is a uniaxial eccentric screw pump that conveys an object to be conveyed by being rotatably inserted into a female screw type stator, wherein the drive shaft end of the drive motor or the drive motor with a reduction gear is decelerated. The drive shaft end is formed in a shape exclusively for the pump, and a disassembled joint head is directly attached thereto. Here, the pump-specific shape refers to a shape that can be inserted from the opening of the motor bracket and can be attached to the tip of the shaft as shown in FIG.

  According to the uniaxial eccentric screw pump of the present invention having the above-described configuration, the joint head portion at the end of the drive shaft can be disassembled so that the connecting rod can be removed and the drive shaft can be inserted and removed. The intermediate rotating shaft could be omitted. As a result, the length of the drive shaft protruding from the bearing around the drive shaft is substantially reduced by the length of the intermediate rotating shaft, so that the load of the bending moment acting on the bearing is reduced, and troubles in the shaft seal portion occur. , And the total length of the pump is shortened to facilitate handling. In addition, by adopting a mechanical seal, the shaft sealing action is stabilized, the unexpected maintenance is unnecessary, and the length of the shaft sealing portion is shortened, thereby eliminating the opening 37a (see FIG. 2) of the motor bracket 37. It can be sealed and is safe even in terms of PL.

  As described in claim 2, instead of the connecting rod and the universal joint, the joint head portion of the flexible rod can be directly connected to the drive shaft end.

  Even if comprised in this way, the effect similar to the uniaxial eccentric screw pump of the said Claim 1 can be anticipated.

  Since the uniaxial eccentric screw pump according to the present invention has the above-described configuration, it has the following excellent effects. That is, since the intermediate rotation shaft, which has been essential in the past, can be omitted, the drive shaft length protruding from the bearing around the drive shaft is substantially reduced by the length of the intermediate rotation shaft. The load of the bending moment acting on the shaft is reduced, the trouble of the shaft seal portion is reduced, the overall length of the pump is shortened, and the handling becomes easy. In addition, the use of a mechanical seal stabilizes the shaft sealing action, eliminates the need for unexpected maintenance, eliminates the opening 37a (see FIG. 2) of the motor bracket 37, and provides a sealed structure that is safe even in terms of PL problems. is there.

  Embodiments of a single-shaft eccentric screw pump according to the present invention will be described below with reference to the drawings.

  FIG. 1 is a longitudinal sectional view, with a part omitted, showing an embodiment of a uniaxial eccentric screw pump.

  As shown in FIG. 1, the uniaxial eccentric screw pump 1 is a horizontal type, and a stator 3 is connected to one end (left side in the figure) opening 2 c of a substantially cylindrical pump casing 2, and a discharge port 4 a is connected to one end of the stator 3. The constituent end studs 4 are connected. The drive motor 6 is coupled to the other end (right side in the figure) opening 2a of the motor bracket 15 connected to the pump casing 2 by a bolt 6b with a flange portion 6a, and the drive shaft 7 is connected to the pump casing from the opening 2a of the motor bracket 15. 2 is inserted inside. In this example, a mechanical seal 8 is disposed as a shaft seal device around a drive shaft distal end portion 7a having a slightly smaller outer diameter than the base end side. The mechanical seal 8 comes into contact with a movable sliding ring 8a urged in the axial direction by a spring 8c and a sliding ring 8b fixed at a fixed position so as to slide integrally with each other. The liquid is prevented from leaking outside.

  A proximal end opening 9b of a cylindrical socket 9a of the universal joint 9 is attached to the end of the drive shaft distal end portion 7a by a pin 10 so as to be integrally rotatable, and a distal end opening 9c is connected to one end of a connecting rod 12 by a thick pin joint 11. The part is connected to bend in all directions. A suction port 2 b is formed substantially above the universal joint 9. The end of the rotor 5 protrudes from an opening 2c at the other end (left side of the figure) of the pump casing 2, and the base end side of the cylindrical socket 14a of the universal joint 14 can be rotated integrally with the rotor end 5a. The tip end side of the cylindrical socket 14a is connected to the other end portion of the connecting rod 12 by a thick pin joint 13 so that it can be refracted in all directions.

  The stator 3 is made of a soft synthetic resin or rubber. As is well known, a female screw hole 3a having an elliptical cross section having a pitch twice that of the rotor 5 is formed in a spiral shape, and a circular cross section is formed in the female screw hole 3a. The male screw type rotor 5 is inserted so as to be rotatable and reciprocally movable in the major axis direction. A metal cylindrical cover 3 b is integrally mounted around the stator 3.

  As described above, the uniaxial eccentric screw pump 1 according to the embodiment of the present invention is configured. This uniaxial eccentric screw pump 1 is a part of the intermediate rotating shaft as compared with the conventional uniaxial eccentric screw pump (see FIG. 2). Is omitted and the length is shortened.

  Now, although not shown in the drawings, instead of the connecting rod 12, a flexible rod (rod made of engineering plastic having flexibility) and a flexible wire joint (bundling a plurality of spring steel wires are used as a core material. After the spring steel wire is spirally wound from one end to the other, the spring steel wire is spirally wound on the spiral direction after changing the spiral direction. If a multi-layered structure is used by repeatedly winding in different directions, the eccentric amount e required for the rotor 5 in the stator 3 is sufficiently allowed even if the universal joint 14 is omitted. In this case, it is necessary to integrally connect a disjoinable joint head portion to one end of a flexible rod or flexible wire joint, and attach it to the end of the drive shaft with a pin or the like so as to be integrally rotatable.

  The uniaxial eccentric screw pump according to the structure of the present invention can be easily changed to a uniaxial eccentric screw pump having a vertical arrangement by using an appropriate mount.

It is the longitudinal cross-sectional view which abbreviate | omitted one part which shows the Example of the uniaxial eccentric screw pump of this invention. It is the longitudinal cross-sectional view which abbreviate | omitted one part which shows the conventional common single axis | shaft eccentric screw pump, The upper half uses the shaft seal part as the mechanical seal, and the lower half uses the gland packing.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Uniaxial eccentric screw pump 2 Pump casing 2a * 2c opening 2b Suction port 3 Stator 4 End stud 5 Rotor 6 Drive motor 7 Drive shaft 7a Tip part of drive shaft 7 8 Shaft seal device (mechanical seal)
8a and 8b sliding ring 8c spring 9 and 14 universal joint 9a and 14a cylindrical socket 10 pin 11 and 13 pin joint 12 connecting rod 15 and 37 motor bracket

Claims (2)

An externally threaded rotor connected via a connecting rod and a universal joint to a drive shaft of a drive motor provided at one end of a motor bracket connected to a pump casing is rotatably inserted into an internally threaded stator and rotated eccentrically. Is a uniaxial eccentric screw pump that conveys the object to be conveyed,
A single-shaft eccentric screw pump characterized in that the drive shaft end of the drive motor or the drive shaft end of the drive motor with a speed reducer is formed in a shape exclusively for the pump, and a disjoinable joint head is directly attached thereto.   The single-shaft eccentric screw pump according to claim 1, wherein instead of the connecting rod and the universal joint, a joint head portion of a flexible rod is directly connected to a drive shaft end.

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