JP2005240590A - Impeller for pump - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an impeller for a pump having a long product life by suppressing the lowering of performance with the elapse of time. <P>SOLUTION: This impeller 11 for the pump is disposed in the casing of the pump feeding a liquid and so formed that its slidable contact part 14 is rotated while coming into slidable contact with the inner peripheral surface of the casing. The impeller 11 for the pump is formed by molding the mixture of a natural rubber with a diene rubber, and the mixing ratio of the natural rubber in the mixture is desirably 50 to 90 mass%, and the mixing ratio of the diene rubber is preferably 50 to 10 mass%. The diene rubber is most preferably a styrene-butadiene copolymer rubber (SBR). <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a pump impeller that is used, for example, for pumping up groundwater or discharging drainage, and is mounted inside a pump.

As this kind of pump impeller, there is known an impeller in which the entire blade portion of the impeller is made of urethane rubber having high wear resistance (see, for example, Patent Document 1). There is also known a structure in which the main body of the impeller is formed of a metal and the surface thereof is coated with chloroprene rubber or the like (see, for example, Patent Document 2).
Japanese Patent Laid-Open No. 9-287592 (pages 2 and 3) JP 11-324940 A (pages 2 and 3)

  By the way, the pump impeller is mounted in the casing of the pump and rotates to pump water from the suction port and discharge it from the discharge port. The impeller is always in contact with water. Urethane rubber is easily hydrolyzed and has poor water resistance, so that if the pump is used for a long period of time, the impeller will crack or chip. When one of the impellers reaches such a state, there has been a problem that the blades of that part are cut and hit all the other blades and eventually all the blades are cut. On the other hand, since chloroprene rubber has high crystallinity, it is poor in flexibility in water, easily cracked, and easily cracked. Therefore, each material has a problem that the product life is short.

  The present invention has been made paying attention to such problems existing in the prior art. An object of the present invention is to provide a pump impeller having a long product life while suppressing deterioration in performance over time.

  In order to achieve the above object, the pump impeller according to the first aspect of the present invention is disposed in the casing of the pump that feeds the liquid, and is configured to rotate while being in sliding contact with the inner peripheral surface of the casing. An impeller for a pump, wherein the impeller is formed by molding a mixture of natural rubber and diene rubber.

  The impeller for a pump according to a second aspect of the invention is the invention according to the first aspect, wherein the blending ratio of the natural rubber in the mixture is 50 to 90% by mass and the blending ratio of the diene rubber is 50 to 10%. % By mass.

  According to a third aspect of the present invention, in the pump impeller according to the first or second aspect, the diene rubber is styrene-butadiene copolymer rubber (SBR).

According to the present invention, the following effects can be exhibited.
According to the pump impeller of the first aspect of the present invention, it is possible to extend the product life by suppressing the deterioration of performance over time.

  According to the pump impeller of the invention described in claim 2, the high modulus and rebound resilience of natural rubber is achieved based on the excellent tensile strength, wear resistance, flexibility, etc. of natural rubber. By supplementing with, the product life can be improved.

  According to the pump impeller of the invention described in claim 3, the balance between the performance such as tensile strength, wear resistance and flexibility and the performance such as modulus and rebound resilience can be best exhibited. The product life can be improved stably.

Hereinafter, embodiments of a pump impeller of the present invention will be described in detail with reference to the drawings.
As shown in FIG. 1, the pump impeller 11 of the present embodiment includes a cylindrical impeller body 12, nine blade plate portions 13 that are formed to protrude from the outer peripheral surface at equal intervals, and the blades. It is comprised from the sliding contact part 14 formed in the front-end | tip of the board part 13 at the column shape. A rotation drive shaft (not shown) is fitted in the impeller body 12, and the impeller body 12 is rotated in a fixed direction integrally with the rotation drive shaft by the rotation of the rotation drive shaft.

  As shown in FIG. 2, the casing 16 of the pump 15 is formed in a substantially cylindrical shape, and the pump impeller 11 is rotatably supported therein. A cylindrical suction cylinder part 17 is provided on the side of the casing 16, a discharge cylinder part 18 is provided on the upper part, and the inner peripheral surface of the casing 16 bulges from the suction cylinder part 17 to the discharge cylinder part 18. The casing 16 is formed thick. When the impeller body 12 is rotationally driven in the clockwise direction indicated by an arrow in FIG. 2 within the casing 16 of the pump 15, the pump impeller 11 rotates while the sliding contact portion 14 is slidably contacted with the inner peripheral surface of the casing 16. . When the impeller body 12 is further rotationally driven, water is sucked from the suction cylinder part 17 by bending the blade plate part 13 together with the sliding contact part 14 from the discharge cylinder part 18 to the suction cylinder part 17 in the rotational direction. It is discharged from the discharge cylinder portion 18.

  The pump impeller 11 can be obtained by molding a mixture of natural rubber (NR) and diene rubber into the shape described above. Natural rubber is a high-molecular substance obtained from a tree of rubber. It is composed of isoprene units and has excellent properties such as tensile strength, tear strength, abrasion resistance, and flexibility. The performance is also high. For this reason, the frictional force when the slidable contact portion 14 of the impeller 11 is slidably contacted with the inner peripheral surface of the casing 16 is large, and the slidable contact portion 14 and the blade plate portion 13 are easily cracked. On the other hand, since the diene rubber has a small modulus, impact resilience, and the like, it is possible to suppress an increase in frictional force when the sliding contact portion 14 of the impeller 11 is in sliding contact with the inner peripheral surface of the casing 16. For this reason, durability can be improved as the impeller 11 for pumps by combining a natural rubber and a diene rubber, and a product life can be improved.

  The diene rubber is a polymer obtained by copolymerizing a monomer having a conjugated double bond such as butadiene or a mixture thereof with a monomer copolymerizable therewith, and is a styrene-butadiene copolymer rubber (SBR). Chloroprene rubber (CR), acrylonitrile-butadiene copolymer rubber (NBR), etc. are used. Among these, the balance of performance such as tensile strength, abrasion resistance, flexibility, etc. and performance such as modulus and impact resilience can be best exhibited, and the product life can be stably improved. From the viewpoint, styrene-butadiene copolymer rubber is most preferable.

  The blending ratio of natural rubber in the mixture of natural rubber and diene rubber is preferably 50 to 90% by weight, the blending ratio of diene rubber is preferably 50 to 10% by weight, and the blending ratio of natural rubber is 70 to 80%. The blending ratio of the mass% and the diene rubber is more preferably 30 to 20 mass%. When the blending ratio of the natural rubber is less than 50% by mass, that is, when the blending ratio of the diene rubber exceeds 50% by mass, the tensile strength and tear strength of the impeller 11 to be obtained become small, and the sliding of the impeller 11 becomes small. Cracks are likely to occur in the contact portion 14 and the blade plate portion 13, and the modulus and rebound resilience become too small and the sag is quick, and the amount of water discharged decreases. On the other hand, when the blending ratio of the natural rubber exceeds 90% by mass, that is, when the blending ratio of the diene rubber is less than 10% by mass, the modulus and rebound resilience become too large, and the sliding contact portion 14 of the impeller 11 becomes the casing. The frictional force at the time of sliding contact with the inner peripheral surface of 16 is increased, and the sliding contact portion 14 and the blade plate portion 13 of the impeller 11 are easily cracked.

  The raw rubber composition for forming the impeller 11 includes a reinforcing material, a softening agent, a vulcanizing agent, a vulcanization accelerator, a processing aid, an anti-aging agent as a compounding agent in addition to the natural rubber and the diene rubber. In addition, a scorch inhibitor is blended. Carbon black, calcium carbonate, clay or the like is used as the reinforcing material. As the softener, mineral oil, vegetable oil, natural resin or the like is used. As the vulcanizing agent, sulfur, metal oxides such as zinc oxide and magnesium oxide, organic peroxides, and the like are used. As the vulcanization accelerator, thiazoles, sulfenamides, thiurams and the like are used. As the processing aid, stearic acid, paraffin or the like is used. As the anti-aging agent, aromatic amines, phenolic compounds and the like are used.

  Usually, the compounding amount of the reinforcing material is 40 to 50% by mass, the compounding amount of the processing aid is 10% by mass or less, and the total amount of the other compounding agents is 10 to 20% by mass. The physical properties of the impeller 11 obtained by molding such a raw rubber composition have a Shore A hardness of 58 to 63 (points) based on JIS K 6253, a tensile strength of 23 to 29 (MPa) based on JIS K 6251, The elongation based on JIS K 6251 is 500 to 600 (%), and the 200% modulus based on JIS K 6254 is 3.5 to 5.0 (MPa).

  Such a raw rubber composition is molded by a known molding method such as a compression molding method, an injection molding method, or the like, and finished to obtain the target pump impeller 11. In this case, extrusion molding and vulcanization can be performed continuously in one stage. As the pump 15 to which the pump impeller 11 is attached in the present embodiment, a rotary pump, a vortex pump, an axial pump or the like is used.

  In order to manufacture the impeller 11 for a pump, first, natural rubber and a diene rubber such as SBR are mixed, and further, as a compounding agent, a reinforcing material, a softening agent, a vulcanizing agent, a vulcanization accelerator, an antiaging agent, and the like. Is mixed to prepare a raw rubber composition. At this time, it is preferable to mix so that natural rubber may be 50 to 90% by mass and diene rubber to be 50 to 10% by mass, and it is preferable to use SBR as the diene rubber. By using a combination of natural rubber and diene rubber as raw rubber, natural rubber can exhibit excellent performance such as tensile strength, tear strength, abrasion resistance, flexibility, etc. The high modulus of modulus and impact resilience, which are disadvantages, can be compensated by diene rubber.

  Then, by injection molding the raw rubber composition, the natural rubber and the diene rubber are melted and integrated and crosslinked to obtain the pump impeller 11 having a shape as shown in FIG. The obtained impeller 11 can exhibit the performance of natural rubber, and the frictional force that is received when the sliding contact portion 14 is in sliding contact with the inner peripheral surface of the casing 16 is suppressed by its own elastic deformation. Therefore, even if the impeller 11 is used in the casing 16 of the pump 15 for a long period of time, its performance can be sufficiently maintained.

The effects exhibited by the above embodiment will be described below.
The pump impeller 11 of the embodiment is formed by molding a mixture of natural rubber and diene rubber. For this reason, the physical properties of the natural rubber and the physical properties of the diene rubber can compensate for each other's disadvantages and exhibit the advantages. Therefore, it is possible to prevent the performance of the pump impeller 11 from decreasing with time and to prolong the product life. . And the pump 15 equipped with this impeller 11 for pumps can suppress the deterioration of the performance at the time of long-term passage compared with the performance (discharge amount) at the time of initial stage.

  The blending ratio of natural rubber in the mixture is 50 to 90% by mass, and the blending ratio of diene rubber is 50 to 10% by mass. Therefore, based on the natural rubber's superior tensile strength, wear resistance, flexibility, etc., the high modulus and rebound resilience of natural rubber are complemented with diene rubber to improve product life. Can do.

  -Since the diene rubber is styrene-butadiene copolymer rubber (SBR), the pump impeller 11 balances performance such as tensile strength, wear resistance, flexibility, and performance such as modulus and impact resilience. Can be exhibited most satisfactorily, and the product life can be stably improved.

  -Since the specific gravity of the impeller 11 for pumps of this embodiment is 1.10-1.20, weight reduction can be achieved compared with chloroprene (specific gravity 1.35-1.40).

(Examples 1 to 4 and Comparative Examples 1 and 2)
As raw materials for the pump impeller 11, natural rubber and SBR, carbon, a vulcanizing agent, a vulcanization accelerator, a processing aid, an anti-aging agent, a scorch inhibiting agent and a vulcanizing agent were blended as shown in Table 1. In Table 1, natural rubber is a ribbed smoked sheet (RSS) RSS No. 3, SBR is 1502 made by Zeon Corporation, carbon black is ISAF made by Showa Cabot Corporation (No. of ASTM is N-220), oxidation Zinc is a vulcanizing agent made by Hakusuitec Co., Ltd., Renogran DPG-80 is a vulcanization accelerator and trade name made by Bayer, Alpha Glan S-80 is a vulcanizing agent made by Tochi Co., Ltd., Renogran CBS- 80 is a vulcanization accelerator, Bayer's product name, stearic acid is a processing aid, manufactured by Nippon Oil & Fats Co., Ltd., Renosin 260 is a processing agent, Bayer's product name, and Nocrak 224 is an anti-aging agent. Product name of Shinsei Chemical Co., Ltd., NOCRACK 6C is an anti-aging agent and product name of Ouchi Shinsei Chemical Co., Ltd., Summit BC is a scorch inhibitor and product name of Nippon Seiwa Co., Ltd. Bu Ace 0355 is a trade name manufactured by Ouchi Shinko Chemical Co., Ltd. in the anti-aging agent.

そして、この配合物を射出成形装置で成形し、加熱して加硫し、ポンプ用インペラ１１を製造した。得られたポンプ用インペラ１１について、JIS K 6253に基づくショアＡ硬度（ポイント）、JIS K 6251に基づく引張強さ（ＭＰａ）、JIS K 6254に基づく１００％モジュラス（ＭＰａ）、JIS K 6254に基づく２００％モジュラス（ＭＰａ）、JIS K 6251に基づく伸び（％）及びJIS K 6255に基づく反発弾性（％）を測定した。その結果を表２に示した。

And this compound was shape | molded with the injection molding apparatus, and it heated and vulcanized | cured and manufactured the impeller 11 for pumps. About the obtained pump impeller 11, Shore A hardness (point) based on JIS K 6253, tensile strength (MPa) based on JIS K 6251, 100% modulus (MPa) based on JIS K 6254, based on JIS K 6254 200% modulus (MPa), elongation (%) based on JIS K 6251, and impact resilience (%) based on JIS K 6255 were measured. The results are shown in Table 2.

表２に示すように、実施例１〜４ではショアＡ硬度、引張強さ及び伸びが高く、１００％モジュラス、２００％モジュラス及び反発弾性が適度に抑制され、実施例２〜４では実施例１に比べて性能のバランスが良く、実施例３では性能のバランスが最も良い。これに対して、ＳＢＲのみの比較例１では引張強さ及び反発弾性が低く、天然ゴムのみの比較例２では１００％モジュラス、２００％モジュラス及び反発弾性が高くなり過ぎている。

As shown in Table 2, in Examples 1 to 4, Shore A hardness, tensile strength and elongation are high, and 100% modulus, 200% modulus and rebound resilience are moderately suppressed. In Examples 2 to 4, Example 1 The balance of performance is better than that of Example 3, and the balance of performance is the best in Example 3. In contrast, Comparative Example 1 with only SBR has low tensile strength and rebound resilience, and Comparative Example 2 with only natural rubber has 100% modulus, 200% modulus and rebound resilience too high.

Moreover, the impeller 11 for pumps obtained in Example 3, Comparative Example 1 and Comparative Example 2 was mounted in the casing 16 of the pump 15 and a durability test was performed. As a result, the continuous use time was less than 30 days in Comparative Examples 1 and 2, and the sliding contact portion 14 of the pump impeller 11 cracked and the pump 15 could not be used. The pump 15 could be used without any problems. In other words, when the pump was used for 8 hours a day, the life of the pump 15 was within 3 months in Comparative Examples 1 and 2, whereas in Example 3, the life was 9 months or longer.
(Examples 5 and 6 and Comparative Example 3)
As raw materials for the pump impeller 11, natural rubber and CR or NBR and carbon, a vulcanizing agent, a vulcanization accelerator, a processing aid, an anti-aging agent, a scorch inhibitor and a vulcanizing agent were blended as shown in Table 3. . In Table 3, natural rubber is a ribbed smoked sheet (RSS) RSS No. 3, chloroprene rubber is DCR-71 made by Denki Kagaku Kogyo Co., Ltd., acrylonitrile-butadiene copolymer rubber is NIPOL DN101L made by Nippon Zeon Co., Ltd., carbon Black is ISAF manufactured by Showa Cabot Co., Ltd. (No. of ASTM is N-220), zinc oxide is a vulcanizing agent, manufactured by Hakusuitec Co., Ltd., Lenogran DPG-80 is a vulcanization accelerator, Bayer's product name, Alpha Glan S-80 is a vulcanizing agent trade name manufactured by Tochi Co., Ltd., Renocran CBS-80 is a vulcanization accelerator and trade name manufactured by Bayer, stearic acid is a processing aid manufactured by Nippon Oil & Fats Co., Ltd., Renogin 260 is Bayer's product name for processing aids, and Paraffin 130 ° F is a processing aid for Nippon Seiwa Co., Ltd. Anti-oxidant, Bayer Co., Ltd., Renogran TMTM-80 is a vulcanization accelerator, Bayer Co., Ltd., Nocrack 224 is an anti-aging agent, Ouchi Shinsei Chemical Co., Ltd., Nocrack 6C Is a brand name manufactured by Ouchi Shinsei Chemical Co., Ltd., Smitade BC is a brand name manufactured by Nippon Seiwa Co., Ltd., and Oceace 0355 is a brand name manufactured by Ouchi Shinsei Chemical Co., Ltd. It is.

そして、この配合物を成形装置に注入し、加熱して成形を行い、ポンプ用インペラ１１を製造した。得られたポンプ用インペラ１１について、JIS K 6253に基づくショアＡ硬度（ポイント）、JIS K 6251に基づく引張強さ（ＭＰａ）、JIS K 6254に基づく１００％モジュラス（ＭＰａ）、JIS K 6254に基づく２００％モジュラス（ＭＰａ）、JIS K 6251に基づく伸び（％）及びJIS K 6255に基づく反発弾性（％）、JIS K 6264に基づく磨耗性（ml）及びJIS K 6258に基づく耐久性硬度変化（ポイント）を測定した。その結果を表４に示した。

And this compound was inject | poured into the shaping | molding apparatus, it heated and shape | molded, and the impeller 11 for pumps was manufactured. About the obtained pump impeller 11, Shore A hardness (point) based on JIS K 6253, tensile strength (MPa) based on JIS K 6251, 100% modulus (MPa) based on JIS K 6254, based on JIS K 6254 200% modulus (MPa), Elongation (%) based on JIS K 6251, Rebound resilience (%) based on JIS K 6255, Abrasion (ml) based on JIS K 6264, and Durability hardness change based on JIS K 6258 (Points) ) Was measured. The results are shown in Table 4.

表４に示すように、実施例５及び６ではショアＡ硬度、引張強さ及び伸びが高く、１００％モジュラス、２００％モジュラス及び反発弾性が良好である。一方、ＣＲのみの比較例３では１００％モジュラス、２００％モジュラス及び反発弾性が高くなり過ぎている。

As shown in Table 4, in Examples 5 and 6, Shore A hardness, tensile strength and elongation are high, and 100% modulus, 200% modulus and rebound resilience are good. On the other hand, in Comparative Example 3 with only CR, the 100% modulus, 200% modulus and rebound resilience are too high.

In addition, this embodiment can also be changed and embodied as follows.
A film such as silicone can be formed on the surface of the pump impeller 11 by a known frictional resistance reduction process. In this case, the frictional resistance on the surface of the impeller 11 can be reduced, and the life can be further extended. Further, assembly and removal when the impeller 11 is accommodated in the casing 16 can be facilitated. In addition, noise during use of the pump 15 can be reduced.

・ A small amount of fluoro rubber, silicone rubber, etc. can be added as raw rubber.
-As natural rubber, what was obtained by modifying it can be used, for example, methyl methacrylate graft rubber, chlorinated rubber and the like.

-The impeller 11 for pumps of this embodiment can also be used when sending liquids, such as cooling liquids, such as brine other than water, and glycols.
Furthermore, the technical idea which can be grasped from the embodiment or another example will be described below.

  The pump impeller according to any one of claims 1 to 3, wherein a film is formed on the surface by a frictional resistance reduction treatment. When configured in this manner, the frictional resistance of the surface can be reduced, and the life can be further extended.

  The pump impeller according to claim 1, wherein the diene rubber is styrene-butadiene copolymer rubber (SBR), chloroprene rubber (CR), or acrylonitrile-butadiene copolymer rubber (NBR).

The perspective view which shows the impeller for pumps in embodiment. Sectional drawing which shows the state which mounted | wore the pump casing with the impeller for pumps.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 ... Impeller for pumps, 15 ... Pump, 16 ... Casing.

Claims (3)

A pump impeller disposed in a casing of a pump for delivering liquid and configured to rotate while sliding on an inner peripheral surface of the casing, and formed by molding a mixture of natural rubber and diene rubber The impeller for pumps characterized by being made. 2. The pump impeller according to claim 1, wherein a blending ratio of the natural rubber in the mixture is 50 to 90 mass% and a blending ratio of the diene rubber is 50 to 10 mass%. The pump impeller according to claim 1 or 2, wherein the diene rubber is a styrene-butadiene copolymer rubber (SBR).

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