JP2002257082A - Liner ring for pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liner ring of a simple and low cost structure, improving a pumping efficiency by controlling leaking loss, and good in assemblability, in a centrifugal pump. SOLUTION: A liner ring surrounding an impeller is formed with soft material, synthetic resin material such as Teflon (registered trademark), and the liner ring is supported movably to a suction casing of the pump by an elastic supporting member such as a rubber made O-ring. When the impeller is displaced from a radial load, a position of the liner ring automatically follows displacement of the impeller. Consequently, a gap between the impeller and liner ring is maintained appropriate even if the impeller displaces. Even if the impeller gets into contact with the liner ring, the contact is maintained light to control wear of the impeller and the liner ring. The liner ring is formed with soft material such as Teflon not to generate a contact noise.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liner ring in a centrifugal pump having a simple and inexpensive structure, capable of suppressing a leakage loss and improving pump efficiency, and having good assembling workability.

[0002]

2. Description of the Related Art Conventionally, in a general centrifugal pump having a single volute structure, a liner ring surrounding an impeller is made of a metal material and is press-fitted and fixed to a suction casing of the pump. In such a pump, when the flow rate at the operating point deviates from the design point, a radial load acts on the impeller. When the main shaft of the pump is long, the impeller is displaced by the radial load and comes into contact with the liner ring, which easily causes abnormal noise or troubles such as abnormal wear of the liner ring and the impeller.

[0003]

In order to avoid contact with the liner ring surrounding the impeller, the gap between the two must be widened, in which case the leakage loss increases and the pump efficiency decreases. Had the disadvantage of doing so. In order to suppress the displacement of the impeller in order to avoid contact, it has been attempted to provide a submerged bearing near the impeller to support the shaft. When the liquid is a low-viscosity liquid such as water, it is difficult to keep the bearing in a fluid lubricated state, and there has been an inconvenience that the bearing is worn out early.

[0004] As another method for avoiding contact between the impeller and the liner ring, the use of guide vanes can suppress the generation of a radial load. Significant reduction in efficiency is not suitable for pumps used in a wide flow range. Similarly,
According to the multiple volute structure, generation of radial load can be suppressed. However, also in this case, there is a disadvantage that the production cost rises.

[0005]

According to the present invention, a liner ring surrounding an impeller is formed of a soft material, for example, a synthetic resin material such as Teflon, and the liner ring is formed by an elastic support element such as a rubber O-ring. The pump is movably supported on the suction casing of the pump. With this configuration, when the impeller is displaced by the action of the radial load, the position of the liner ring itself automatically follows the displacement of the impeller. Therefore, even if the impeller is displaced,
The gap between the impeller and the liner ring can be properly maintained. Further, since the position of the liner ring follows the displacement of the impeller, even if the impeller and the liner ring come into contact with each other, light contact is maintained, and wear of the impeller or the liner ring can be suppressed. Further, since the liner ring is made of a soft resin material such as Teflon, no noise is generated at the time of contact.

The elastic support element disposed between the liner ring and the suction casing of the pump includes (1) an elastic support element for movably supporting the liner ring, and (2) a sealing element between the liner ring and the suction casing. It has two functions.

[0007]

The above configuration of the present invention is particularly suitable as a linering structure of a single volute pump having a long main shaft and generating a radial load. According to the conventional structure, the liner ring is assembled into the suction casing by press-fitting. However, according to the present invention, the liner ring is movably mounted on the suction casing by an elastic material such as an O-ring. And
Workability is improved.

[0008]

FIG. 1 is a sectional view of a pump having a liner ring of the present invention mounted between a suction casing and an impeller of the pump, and FIG. 2 is an enlarged sectional view of a liner ring portion. An annular liner ring 4 is movably supported by an O-ring 5 on the suction casing 3 of the pump in a portion facing the impeller 3 inside the suction casing 2 of the single volute pump 1.

The liner ring 4 is formed of a soft synthetic resin material such as Teflon and has a substantially rectangular cross section as shown in FIG.
As shown in FIG. 1, slot holes 6 and 7 are formed in the liner ring 4 and the side surface of the suction casing 2 opposed thereto. A slot 6 'for accommodating the O-ring 5 only on the outer side of the liner ring 4 as shown in FIG. 3 or only on the inner side of the circumference of the suction casing 2 as shown in FIG.
7 'can also be provided. For comparison, FIG. 5 shows an enlarged cross section in which a conventional metal liner ring is mounted on a suction casing. The main shaft 8 of the pump is supported by a sleeve 9, and a mouth ring 10 of the impeller 3 faces a metal liner ring 11. In FIG. 1, reference numeral 12 denotes a discharge casing.

The O-ring 5 is formed of an elastic material such as rubber, and functions as an elastic supporting element for movably supporting the liner ring 4 and also as a sealing element between the liner ring 4 and the suction casing 2. .

[Brief description of the drawings]

FIG. 1 Between a suction casing of a pump and an impeller,
It is sectional drawing of the pump equipped with the liner ring of this invention.

FIG. 2 is an enlarged sectional view showing a liner ring of the present invention.

FIG. 3 is an enlarged sectional view showing another embodiment of the liner ring of the present invention.

FIG. 4 is an enlarged sectional view showing still another embodiment of the liner ring of the present invention.

FIG. 5 is an enlarged sectional view showing a conventional liner ring.

[Explanation of symbols]

 Reference Signs List 1 pump 2 suction casing 3 impeller 4 liner ring 5 O-ring 6, 6'7, 7 'slot 8 main shaft 9 sleeve 10 mouth ring 11 metal liner ring 12 discharge casing

Claims (2)

[Claims] In a centrifugal pump having a single volute structure, a liner ring surrounding an impeller is formed of a soft material, and the liner ring is movably supported by a resilient support element with respect to a suction casing of the pump. A liner for a pump, characterized in that: 2. The pump according to claim 1, wherein the liner ring is formed of a soft synthetic resin material such as Teflon, and is movably supported on a suction casing of the pump by an elastic support element formed of a rubber O-ring. A liner for a pump, characterized in that: