JPS61142393A - Wear resistant impeller - Google Patents

Abstract

PURPOSE:To improve resistance to wear and power transmitting ability, by a method wherein a screw groove for coupling to a shaft is formed in a bush coupled to the boss part of an impeller, made of wear resistant white cast iron, by shrink fitting. CONSTITUTION:An impeller 10 is made of a nickel.chrome series or high chrome series wear resistant white cast iron material, and a bush 20 is coupled to a boss part 12 of the impeller 10 by shrink fitting. A screw groove 21, by means of which a bush is threadely engaged with a shaft 14, is formed in a bush 20. This increases engagement performance of the bush with the shaft by means of the screw groove formed in the bush, and improves resistance to wear thanks to the special material of the impeller.

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention is characterized by having a wear-resistant structure suitable for transporting liquid containing highly hard materials such as gravel, such as a dredging pump. The present invention relates to a wear-resistant insulator having the following characteristics.

(Prior art) In pumps such as dredging pumps that transport all of the liquid containing highly hard substances such as gravel, wear of the inner pipe due to the highly hard substances in the transported liquid becomes a problem, so the conventional dredging pump The impeller of the pump has a blade part (1) as shown in Figure 2.
The boss part (2) that fits into the shaft (4) is molded into an integral structure, and manufactured by pouring molten steel, which is a material that is relatively easy to machine. Welding is carried out using a hardened adhesive rod made of martensitic, martensitic, or tungsten carbide materials, resulting in a structure that maintains full wear resistance. Note that (5) in the figure is a casing.

(High point of the prior art) In the conventional impeller, it is necessary to periodically repair the hardfacing applied to the parts that are subject to severe wear.
It cannot be operated continuously for a long time. There are quality problems due to variations in hardfacing construction, and performance, that is, sufficient wear resistance, cannot be obtained. There are problems such as.

However, if the impeller is integrally molded from white cast iron, the white cast iron is very hard and brittle, making it difficult to shape the fitting portion to the shaft, thread machining, etc., which poses a problem in practical use.

(Object of the Invention, Means for Solving Problems) The present invention was developed to solve the above-mentioned problems in conventional impellers.
It is characterized by a structure that includes an impeller made of chrome-based or high-chromium wear-resistant white cast iron, a bushing that is shrink-fitted to the boss portion of the impeller, and a screw groove provided in the bushing for coupling to the shaft. By making the impeller made of nickel-chromium or high-chromium wear-resistant pure white cast iron, the wear resistance of the entire insulator, except for the bushings, which have no particular effect on wear, is dramatically improved. By shrink-fitting a bushing to the part, it is integrated without slipping Vt between the two, and furthermore, by using the bushing, it is easy to form a thread groove and improve the coupling performance to the shaft, making it a wear-resistant white cast iron type. The object of the present invention is to significantly improve the wear resistance, power transmission performance, and reliability of the impeller, thereby solving the above-mentioned problems and providing a wear-resistant alloy.

(Embodiment of the Invention) An embodiment of the present invention is shown in Fig. 1, in which 01 is an impeller, and the impeller Q1 is made of wear-resistant white cast iron material of nickel-chromium type or high chromium type. It is integrally cast and manufactured, and the inn R (1
The bush (13) is connected to the bush (13) by shrink fit, and is further provided with a ninth screw groove (C2N) that is threaded into the bush (4).

To explain in more detail, the impeller OI is one in which the blades, the boss part (121, etc.) are integrally cast and manufactured, and for example, C: 3.4, Si: 1.6, Mle:
0.49, P, S: 0.020, lJt: 6
．． 0, Cτ: 9.1 (weight) ξ-cent, hardness: A nickel-chromium based wear-resistant white cast iron material having a hardness of H875-78, or a high chromium-based wear-resistant white cast iron material.

Friend, the bush (a) is, for example, C: 0.20°SL: 0.23. Mm: 1.0. P, S: 0.03. N
i:1,5. Or: 0.4°MO: 0.2. V:0.2
Yo 9 fx Le Mlf'Hersey )ノ Ni -Mo-
It can be made of V-steel material, and a material with good workability can be used. Furthermore, the shaft (4) is, for example,
C: 0.2. Si:0.23. M: Q, 8. P,
S:0.03. NL:3.0. qr:3.0. MO:
A material having a weight percent of 0.5 is used.

Further, the ear dowel 01 is made by casting the blade part, boss part, etc. as an integral structure in a sand mold, then dismantling the mold 7, applying stainplast to the cast surface, and then applying 210C.
X 4 Hr, F', C (D low temperature annealing 11i L, can be manufactured by machining the boss part to the specified dimensions, and on the other hand, prepare a bush +201 with a thread groove (2υ) by threading it to the specified dimensions. , After heating the impeller (boss part (125 side) of 101 to about 200 C, the pusher 5-■
The impeller (1α) is constructed by fitting all the boss portions (121), covering the entire body with an ice stick, slowly cooling it, and integrally joining the bush mt-shrink fit.

In addition, in the shrink-fitting method of the bushings, unless all proper shrink-fitting conditions are understood, slippage will occur on the mating surfaces of the boss portion and the bushings, so a rotational torque test was conducted. The shrink fit was processed so that the interference was 0.30 to 0.35 mm.

(Function) The embodiment of the present invention has the above-described configuration, and as a result, T = 8, which is the allowable torque of a normal impeller.
000 to 9-m 25-30T-In which is more than 3 times
・Even if the rotational torque of the wind is applied, the generated stress will be approximately R
Even at 1', it becomes less than 9/mu2, which eliminates slippage on the mating surface and enables complete power transmission.

By shrink-fitting the bolts and bushings, the main body of the impeller can be made of monolithically cast nickel-chromium or high-chromium wear-resistant white cast iron, and its wear resistance is better than that of the conventional one. In the overlay welding type infiller, repairs are required at intervals of 7 to 10 days, but in the present invention, repairs are performed continuously at intervals of 7 to 10 days.
Almost no wear was observed even after several months of operation.

(Effects of the Invention) As described above, in the present invention, an impeller is made of nickel-chromium or high-chromium wear-resistant pure white cast iron, a bushing is shrink-fitted to the boss portion of the impeller, and a shaft is attached to the bushing. Since the threaded groove for coupling to the impeller is designed in a double configuration, by shrink-fitting the bushing to the boss of the impeller, there will be no slippage between the two, and the threaded groove provided on the bushing will improve the coupling performance to the shaft. By using the bushing, the bushing can be made of integrally formed nickel-chromium or high-chromium wear-resistant pure white cast iron, which improves wear-resistance.
Power transmission performance and reliability have been significantly improved.

Although the present invention has been described above with reference to embodiments, it goes without saying that the present invention is not limited to such embodiments, and that various design modifications can be made without departing from the spirit of the present invention. .

[Brief explanation of the drawing]

11 is a partial cross-sectional view of a wear-resistant inlet showing an embodiment of the present invention, and FIG. 2 is a cross-sectional view showing a conventional example. 4: Shaft 10: In is Ra 12: Boss part 20: Push 21: Screw groove Sub-agent Patent attorney Shige Okamoto 3 people outside the kiln Figure 1 Figure 2

Claims (1)

[Claims] The impeller is equipped with a nickel-chromium or high-chromium wear-resistant white cast iron impeller, a bush that is shrink-fitted to the boss of the impeller, and a screw groove for coupling to the shaft provided in the bush. Features a wear-resistant impeller.