CN111878409A - Double-suction split pump and manufacturing method thereof - Google Patents

Abstract

The invention relates to a double-suction split-middle pump (100), the double-suction split-middle pump (100) has two half-type horizontal bearing seats (200) arranged on both sides of a pump body (300), and the pump body ( 300) includes a lower pump body (310) and an upper pump cover (320) for accommodating the pump shaft and the impeller, and an axial bearing gland (210) is installed on the outside of the horizontal bearing seat (200) to It is used to provide the axial rotor fixing function for the two-half type horizontal bearing seat (200). The invention also relates to a manufacturing method of a double-suction split pump.

Description

Double-suction split pump and manufacturing method thereof

technical field

The invention relates to a double-suction split pump and a manufacturing method thereof.

Background technique

As an important form of centrifugal pump, double-suction split pump is widely used in engineering because of its high lift and large flow. The impeller of this pump type is actually a combination of two back-to-back impellers, and the water flow from the impellers merges into a volute. The pump casing of the double-suction split-middle pump is horizontally split, which is convenient for inspection and maintenance. In theory, the impeller structure of the double-suction split-middle pump is symmetrical, without axial force, and the operation is relatively stable. Figure 1 shows the traditional single-stage double-suction split-middle pump. Open pump design structure.

In fact, the traditional design of the bearing seat of the split pump is either too simple, resulting in low strength and high vibration during operation, or the structure is too complicated, resulting in high production cost. The mating surface of the bearing seat and the pump body is mostly semi-circular. It is easy to produce collisions in the middle, the processing is relatively difficult, the precision is difficult to control, and the processing cost is high; the bearing seat and the pump body are processed separately, which will also lead to the accumulation of at least two processing errors, which will affect the concentricity of the rotor installation and the pump operation to a certain extent. Figure 2 shows the structure of the two-half horizontal bearing seat of the traditional split pump.

The horizontal bearing seat selected for the split pump is usually expected to be a generalized and standardized bearing seat product, so as to reflect the cost advantage compared with the traditional bearing seat designed by the traditional pump factory. According to the production cost survey, the unit price of the standard horizontal bearing seat is only 1/4 to 1/2 of the unit price of the traditional bearing seat; Put it on the pump body and then lock 2 to 4 bolts, the plane processing is relatively simple, only one milling process, the risk of processing errors is low, and the accuracy is easy to control.

However, after years of experience in R&D, production and actual project performance, the applicant has realized that the disadvantages of using universal and standardized bearing housing products in the design structure of the existing split pump are also obvious. First, the use of a common, standardized housing product results in no rotor axial positioning capability. As shown in Figure 3, the generalized and standardized bearing seat product is only composed of the lower half bearing seat and the upper half bearing seat in structure. The bearing/rotor can only be installed between the outer ring of the bearing and the inner hole of the bearing seat. The two axial positioning rings are partially fixed. The positioning ring must have a width machining error, and the width of the bearing inner hole must also have a machining error. The accumulation of the three errors must exist, and there must be large or small gaps after installation, with a maximum of 0.1～ 0.2mm.

Secondly, when the pump rotor is installed, workers need to manually adjust the horizontal and vertical concentricity of the bearing seats at both ends. Inconsistent installation quality can cause the bearings at both ends of the rotor to have variable angles, which can lead to additional harmful loads on the bearings.

The above two main problems all lead to the occurrence of the shaft jumping phenomenon of the split pump during operation, the high bearing temperature in actual operation, the transverse shear of the grease, the easy failure of lubrication, and the shortened bearing life.

SUMMARY OF THE INVENTION

In order to overcome the above-mentioned defects of the prior art of the split-middle pump, and at the same time retain the advantages of the cost and installation convenience of the horizontal bearing seat configuration, the present invention provides a double-suction split-middle pump, which has two halves arranged on both sides of the pump body. A horizontal bearing seat, the pump body includes a lower pump body and an upper pump cover for accommodating the pump shaft and the impeller, wherein an axial bearing gland is added to the side of the horizontal bearing seat to be used for The two-half type horizontal bearing seat provides the axial rotor fixing function.

In the prior art, due to cost considerations, the adopted two-half horizontal bearing seat does not have an axial positioning function. The upper half bearing seat of the two-half horizontal bearing seat is placed on the lower half bearing seat, which is positioned and fastened by bolts and tapered pins, but cannot provide axial positioning for the rotor. After the bearing gland installed in the present invention is fastened by bolts on the outer end face, a gap of 0.5-0.8 mm is left between the inner end face and the end face of the bearing seat, so as to ensure the axial fixation of the bearing/middle pump rotor.

Therefore, the inventor provides support for the axial positioning of the rotor in a low-cost manner by adding a bearing gland to the outside of the existing generalized and standardized bearing housing, which is not obvious to those skilled in the art . On the one hand, in the prior art, due to the symmetrical impeller and pump body design used in the double-suction split pump, the axial force is theoretically small, and those skilled in the art would not think of adding additional bearing glands. On the other hand, in the prior art, partial fixation of the bearing/rotor is achieved by installing 1-2 axial locating rings between the bearing outer ring and the inner hole of the bearing seat, since the installation of the pump rotor requires workers to manually adjust the bearings at both ends The horizontal and vertical concentricity of the seat, this manual adjustment must have an installation error objectively. As far as the impact of the shaft jumping in the operation of the split pump is concerned, the installation error is related to the positioning ring and the width of the bearing inner hole. The machining error Therefore, in the case that manual adjustment is still required in the installation of the pump rotor, those skilled in the art have no motivation to eliminate the machining error of the width of the positioning ring and the inner hole of the bearing, so they will not think of arranging the bearing gland. to intentionally limit axial movement.

In order to overcome the installation error caused by manual adjustment, in an implementation form of the double-suction split pump according to the present invention, the inner holes of the two horizontal bearing seats and the pump body of the double-suction split pump done together in one boring operation. Since the inner hole of the horizontal bearing seat and the pump inner hole of the double-suction split pump are processed in one boring process, the inner holes of the two horizontal bearing seats of the "pump body + bearing seat" machined finished product can be machined. The concentricity of the holes is in the range of 0-0.05mm, which is far better than the accuracy of manually adjusting the horizontal and vertical concentricity of the horizontal bearing seats at both ends in the prior art. In the prior art, the concentric level of the rotor support that can be achieved by manual adjustment of the centering and the concentric level of the bearing support at both ends of the rotor in the traditional middle-open pump structure design is limited, and the concentricity is above 0.1mm, and the maximum can reach 0.2-0.3mm. In addition, in the technical solution according to the present invention, since the inner hole of the whole piece is processed, there is no problem of accumulation of processing errors.

Therefore, in the technical solution of the present invention, it is more convenient to install the rotor, without manual adjustment and alignment, and only need to directly hoist the rotor and then cover the upper half bearing seat, locking bolts and bearing seat press cover.

Bearing glands can be designed to be installed either on the outside of the bearing housing or on the inside of the bearing housing. Preferably, however, the axial bearing glands are mounted on the outside of the two horizontal bearing seats. Because the conditions on site are usually limited, it is very difficult and time-consuming to remove and install bearings. For installation, on-site maintenance and replacement of spare parts, the bearing glands are arranged on the outside to save a lot of time and effort. If the gland is damaged during installation or on-site pump maintenance (for example, the labyrinth oil seal of the inner ring is easily damaged), the damaged gland arranged on the outside can be directly replaced with a new gland without removing the bearing.

According to another aspect of the present invention, the present invention provides a method for manufacturing a double-suction split-middle pump, the double-suction split-middle pump has two half-type horizontal bearing seats arranged on both sides of the pump body, and provides machining with only an inner hole left. The bearing seat semi-finished product; the bearing seat semi-finished product is connected and locked with the support platform of the pump body of the double-suction split pump through bolts, and the inner thread tapered pin is installed in the pump body to fix the position of the bearing box ; and the boring process of the inner hole of the pump body of the double-suction split pump and the inner holes of the two horizontal bearing seats are completed together in one boring process.

In the inner hole boring process, the semi-finished bearing seat (only the inner hole machining allowance is left) is connected and locked with the support platform of the pump body by bolts, and after the inner thread taper pin is installed to fix the position of the bearing box, the inner hole of the pump body is connected with the two parts. The bores of each housing are bored together in one boring operation. The improved concentricity level can greatly improve the stress condition of the split pump bearing during operation, eliminate the angle between the center lines at both ends of the rotor and the phenomenon of axial jumping, reduce or eliminate additional harmful loads caused by poor concentricity, and then Reduce bearing temperature, improve lubricating conditions, and prolong bearing life, thereby further reducing the vibration of the split pump in actual operation, and the operation is more stable and reliable.

In an embodiment of the method for manufacturing a double-suction split-split pump according to the present invention, an axial bearing press cover is added to the side surfaces of the two horizontal bearing seats. The added bearing housing gland can provide the axial rotor fixing function for the traditional two-half horizontal bearing housing, eliminating the biggest cause of rotor shaft jumping from the structural root. Bearing glands can be designed to be installed either on the outside of the bearing housing or on the inside of the bearing housing. Preferably, however, the axial bearing glands are mounted on the outside of the two horizontal bearing seats. Because the conditions on site are usually limited, it is very difficult and time-consuming to remove and install bearings. For installation, on-site maintenance and replacement of spare parts, the bearing glands are arranged on the outside to save a lot of time and effort. If the gland is damaged during installation or on-site pump maintenance (for example, the labyrinth oil seal of the inner ring is easily damaged), the damaged gland arranged on the outside can be directly replaced with a new gland without removing the bearing.

As mentioned above, according to the design of the two-half horizontal bearing seat and the supporting processing technology of the present invention, the existing middle-open pump is solved by adding the design of the axial bearing gland and the combined boring processing technology of the bearing seat and the pump body. There are problems such as lack of axial fixation of the middle rotor, poor concentricity of rotor installation, high bearing temperature, and shortened bearing life.

Description of drawings

Figure 1 illustrates the design structure of a traditional single-stage double-suction split pump;

Figure 2 shows the structure of the two-half horizontal bearing seat of the traditional split pump;

3A and 3B illustrate that in the horizontal bearing seat structure in the prior art, the axial positioning function is realized by the axial positioning ring;

4A and 4B illustrate the two-half type horizontal bearing seat of the double-suction split pump provided by the present invention;

5A and 5B illustrate the processing technology of the double-suction split pump provided by the present invention.

Detailed ways

The present invention will be explained in detail below with reference to the accompanying drawings and embodiments.

3A and 3B illustrate that in the horizontal bearing seat structure in the prior art, the axial positioning function is realized by the axial locating ring. As shown in FIG. 3B, in the horizontal bearing seat structure in the prior art, Part of the bearing/rotor is fixed by installing 1-2 axial locating rings 400 between the outer ring of the bearing and the inner hole of the bearing seat. Since the installation of the pump rotor requires workers to manually adjust the horizontal and vertical directions of the bearing seats at both ends Concentricity, this manual adjustment must objectively have installation errors.

4A and 4B illustrate the two-half type horizontal bearing seat of the double-suction split-middle pump provided by the present invention. As shown in FIGS. 4A and 4B , the horizontal bearing seat 200 of the double-suction split-middle pump provided by the present invention An axial bearing gland 210 is installed on the outside to provide the axial rotor fixing function for the two-half horizontal bearing seat 200. It should be pointed out that the upper half of the two-half horizontal bearing seat is placed in the lower half. On the bearing seat, bolts and tapered pins are used for positioning and fastening, but they cannot provide axial positioning for the rotor.

After the axial bearing gland 210 is fastened by bolts on the outer end face, the clearance H between the inner end face of the axial bearing gland 210 and the end face of the bearing seat is 0.5-0.8 mm, which ensures the axial fixation of the bearing/middle pump rotor.

Axial bearing glands 210 are installed on the outside of the two horizontal bearing housings 200. The added bearing housing glands 210 can provide the axial rotor fixing function for the traditional two-half horizontal bearing housings, eliminating the rotor from the structural root. The biggest cause of shaft kick.

FIGS. 5A and 5B illustrate the processing technology of the double-suction split-middle pump provided by the present invention. As shown in FIGS. 5A and 5B , the double-suction split-middle pump 100 provided by the present invention has two The half-type horizontal bearing seat 200, the pump body 300 includes a lower pump body 310 and an upper pump cover 320, which are used to accommodate the pump shaft and the impeller, so that the inner holes of the two horizontal bearing seats 200 are connected to the pump of the double-suction middle-opening pump 100. The inner bore of the body 300 is completed together in one boring operation.

During processing, the semi-finished bearing seat is connected and locked with the support platform of the pump body 300 of the double-suction split pump 100 by bolts, and the taper pin with the internal thread is installed in the pump body 300 to fix the position of the bearing box, together in a boring process. The boring process of the inner hole of the pump body 300 of the double-suction split pump 100 and the inner holes of the two horizontal bearing seats 200 is completed.

Since the inner hole of the horizontal bearing seat 200 and the inner hole of the pump body 300 of the double-suction split pump 100 are processed in one boring process, the two horizontal The concentricity of the inner hole of the horizontal bearing seat is in the range of 0-0.05mm, which is far better than the accuracy of manually adjusting the horizontal and vertical concentricity of the horizontal bearing seat at both ends in the prior art.

In the prior art, the concentric level of the rotor support that can be achieved by manual adjustment of the centering and the concentric level of the bearing support at both ends of the rotor in the traditional middle-open pump structure design is limited, and the concentricity is above 0.1mm, and the maximum can reach 0.2-0.3mm.

In addition, due to the inner hole machining of the whole piece, there is no problem of accumulation of machining errors.

The improved concentricity level can greatly improve the stress condition of the split pump bearing during operation, eliminate the angle between the center lines at both ends of the rotor and the phenomenon of axial jumping, reduce or eliminate additional harmful loads caused by poor concentricity, and then Reduce bearing temperature, improve lubricating conditions, and prolong bearing life, thereby further reducing the vibration of the split pump in actual operation, and the operation is more stable and reliable.

The design of the two-half horizontal bearing seat and the matching processing technology of the present invention solve the problem of the lack of the axial direction of the rotor in the existing middle-opening pump by adding the design of the axial bearing gland and the combined boring processing technology of the bearing seat and the pump body. Fixing, poor rotor installation concentricity, high bearing temperature, shortened bearing life, etc.

The preferred embodiments of the present invention have been described above, but the spirit and scope of the present invention are not limited to the specific contents disclosed herein. Those skilled in the art can arbitrarily combine and expand the above embodiments according to the teachings of the present invention to make more implementations and applications within the spirit and scope of the present invention. The spirit and scope of the present invention are not limited by the specific embodiments but by the claims.

List of reference signs

100 double suction split pump

200 Horizontal bearing housing

210 Axial bearing gland

300 pump body

310 lower pump body

320 Upper pump cover

400 Locating Ring

H Clearance between the inner end face of the axial bearing gland and the end face of the housing.

Claims (6)

1. A double-suction split-middle pump (100), the double-suction split-middle pump (100) has two half-type horizontal bearing seats (200) arranged on both sides of a pump body (300), and the pump body (300) ) includes a lower pump body (310) and an upper pump cover (320) for accommodating the pump shaft and the impeller, characterized in that, An axial bearing press cover (210) is installed on the side surface of the horizontal bearing seat (200), so as to provide the axial rotor fixing function for the two-half horizontal bearing seat (200). 2. The double-suction split-middle pump according to claim 1, characterized in that the inner holes of the two horizontal bearing seats (200) and the pump body (300) of the double-suction split-middle pump (100) The inner holes are completed together in one boring operation. 3 . The double-suction split pump according to claim 1 , wherein the axial bearing gland ( 210 ) is installed on the outer side of the horizontal bearing seat ( 200 ). 4 . 4. A method for manufacturing a double-suction split-middle pump, the double-suction split-middle pump (100) having two half-type horizontal bearing seats (200) arranged on both sides of a pump body (300), characterized in that, Provide semi-finished bearing housing with only inner hole machining allowance; connecting and locking the semi-finished bearing seat with the support platform of the pump body (300) of the double-suction split pump (100) through bolts, and installing an internally threaded tapered pin into the pump body to fix the position of the bearing box; The inner holes of the pump body (300) of the double-suction split-suction pump (100) and the inner holes of the two horizontal bearing seats are completed together in one boring process. 5 . The method for manufacturing a double-suction split pump according to claim 4 , further comprising adding axial bearing glands ( 210 ) on the sides of the two horizontal bearing seats ( 200 ). 6 . 6 . The method for manufacturing a double-suction split pump according to claim 5 , further comprising installing an axial bearing gland ( 210 ) on the outer sides of the two horizontal bearing seats ( 200 ). 7 .

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