Connecting structure for split surfaces of double-shell multi-stage pump
By using an outer shell and an inner shell to form a sealed cavity in a double-shell multistage pump, and by utilizing a limiting mechanism and an anti-rotation positioning block design, the problems of high casting difficulty and high cost caused by the open-face connection in the inner shell are solved, achieving the effect of structural stability and low transportation cost.
Patent Information
- Application Number
- CN202520159061.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-23
- Publication Date
- 2025-11-28
- Estimated Expiration
- 2035-01-23
AI Technical Summary
The open-face connection method of the inner casing of the existing double-casing multistage centrifugal pump leads to an increase in radial dimension, which is difficult to cast and costly.
The outer cylinder and the inner shell form a sealed cavity. The inner shell is designed with a limiting mechanism and an anti-rotation positioning block, combined with clearance fit and fastening device, which reduces the casting difficulty and the radial dimension.
This design achieves a connection structure that reduces the difficulty of casting the inner shell, stabilizes the structure, and lowers transportation costs, thereby reducing the overall radial dimension and weight of the pump.
Smart Images
Figure CN223608929U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to a connecting structure, concretely relates to a connecting structure of double -shell multistage pump middle open surface that has reduced the casting difficulty of inner casing middle open surface, reduced the radial dimension of inner casing, stable structure, low transportation cost. BACKGROUND
[0002] Double -shell multistate centrifugal pump is generally applied in petrochemical industry, electric power industry, is especially used to transport high temperature, high pressure chemical medium. The double -shell multistate centrifugal pump of prior art, such as BB5 type pump, inner casing is divided into sectional type or middle open type. The connecting mode of middle open surface of middle open type inner casing is as shown in Figure 7 The middle open surface is extended, is made into flange surface, is processed thread hole on the flange surface, is connected with screw post again. This kind of connecting mode leads to the radial dimension of inner casing to be big, increases the overall radial dimension of pump, increases cost. At the same time, the casting difficulty is increased. CONTENT OF UTILITY MODEL
[0003] In view of above problem, the main purpose of the utility model is to provide a connecting structure of double -shell multistage pump middle open surface that has reduced the casting difficulty of inner casing middle open surface, reduced the radial dimension of inner casing, stable structure, low transportation cost.
[0004] The utility model solves the above technical problem through the following technical scheme: a connecting structure of double -shell multistage pump middle open surface, the connecting structure of double -shell multistage pump middle open surface includes: inner casing, the outer cylinder of being sleeved on the outside of inner casing.
[0005] The outer cylinder is provided with import flange, export flange, and the outer cylinder and the pump cover jointly constitute a sealed cavity, and the inner casing is sealed in the sealed cavity.
[0006] The rotor part is installed inside the inner casing, and the transition flow channel of the inner casing jointly constitutes the flow part of the pump.
[0007] The inner casing includes an upper casing and a lower casing, and the upper casing and the lower casing are arranged in a central symmetry.
[0008] An inner casing anti-rotation positioning block is arranged on the high-pressure side end surface of the inner casing, and an inner casing circumferential positioning block is arranged on the middle plane of the upper casing and the lower casing.
[0009] In the specific embodiment of the utility model, the connecting device includes an inner joint surface and an outer joint surface; the inner joint surface and the outer joint surface are in clearance fit, the inner joint surface is provided with a threaded hole thereon; the outer joint surface is provided with a corresponding through hole thereon; the connecting device is provided with a fastening device, and the fastening device includes a plurality of gaskets and a hexagonal socket head screw.
[0010] In the embodiment of the utility model, each limiting mechanism comprises a wedge block, a trapezoidal slot and two set screws; the wedge block is installed in the trapezoidal slot and is tightly pressed by the set screws.
[0011] In the embodiment of the utility model, the taper angle θ of the wedge block is 5-12 °.
[0012] In the embodiment of the utility model, the taper angle of the trapezoidal slot and the taper angle θ of the wedge block are the same.
[0013] In the embodiment of the utility model, the small end surface of the trapezoidal slot and the small end surface of the wedge block are spaced apart by 2-5 mm.
[0014] In the embodiment of the utility model, the large end surface of the trapezoidal slot and the large end surface of the wedge block are spaced apart by 1 / 3 of the width of the wedge block.
[0015] In the embodiment of the utility model, the length of the trapezoidal slot is 2-5 mm longer than the length of the wedge block.
[0016] The utility model discloses a positive progress effect lies in: the connecting structure of the double-shell multistage pump of the utility model compared with the common technology has the following advantages: the connecting mode of the utility model, reduces the casting difficulty of the inner shell middle open surface, and the design mode such as limiting structure, inner shell anti-rotation positioning block, inner shell circumferential positioning block reduces the casting difficulty of the utility model, and the structure is stable, and the transportation cost is low. BRIEF DESCRIPTION OF DRAWINGS
[0017] Figure 1 It is the whole structure schematic diagram of the utility model.
[0018] Figure 2 It is the inner shell middle open surface structure schematic diagram in the utility model.
[0019] Figure 3 It is the connecting device schematic diagram in the utility model.
[0020] Figure 4 It is the limiting structure schematic diagram in the utility model.
[0021] Figure 5 It is the limiting structure cross section schematic diagram in the utility model.
[0022] Figure 6-1 It is the wedge block structure schematic diagram in the utility model.
[0023] Figure 6-2 It is the position schematic diagram of the wedge block taper angle θ in the utility model.
[0024] Figure 7The whole structure schematic diagram of the prior art.
[0025] The following is the name corresponding to the label in the utility model:
[0026] The shell body 1, the pump inlet 11, the pump outlet 12, the inner shell 2, the upper shell 21, the lower shell 22, the middle split surface connecting device 23, the inner connecting surface 231, the outer connecting surface 232, the gasket 234, the inner hexagonal cylindrical head screw 235, the limiting mechanism 24, the wedge block 241, the set screw 242, the trapezoidal groove 243, the inner shell anti-rotation positioning block 25, the inner shell circumferential positioning block 26, the pump cover 3, the rotor component 4. Specific implementation
[0027] The preferred embodiments of the utility model are given below in combination with the drawings to specifically explain the technical scheme of the utility model.
[0028] Figure 1 The whole structure schematic diagram of the utility model, Figure 2 The inner shell middle split surface structure schematic diagram of the utility model is shown as follows, Figure 1-2 The split surface connecting structure of the double-shell multi-stage pump provided by the utility model comprises an inner shell 2 and an outer cylinder 1 sleeved outside the inner shell 2. The outer cylinder 1 is provided with an inlet flange 11 and an outlet flange 12. The outer cylinder 1 and the pump cover 3 jointly form a sealed cavity. The inner shell 2 is sealed in the sealed cavity. The rotor component 4 is installed inside the inner shell 2 and jointly forms the flow component of the pump with the transition flow channel of the inner shell 2. The inner shell 2 comprises an upper shell 21 and a lower shell 22. The upper shell 21 and the lower shell 22 are arranged in a central symmetry. A middle split flange surface is arranged between the upper shell 21 and the lower shell 22. The two sides of the middle split flange surface are provided with connecting devices 23. One limiting mechanism 24 is arranged at each of the four corners of the middle split surface. The inner shell anti-rotation positioning block 25 is arranged on the high-pressure side end surface of the inner shell. The inner shell circumferential positioning block 26 is arranged on the middle plane of the upper shell 21 and the lower shell 22.
[0029] Figure 3 The connecting device schematic diagram of the utility model is shown as follows, Figure 3 The connecting device 23 comprises an inner connecting surface 231 and an outer connecting surface 232 (see Figure 2 ). The inner connecting surface 231 and the outer connecting surface 232 adopt a clearance fit. The inner connecting surface 231 and the outer connecting surface 232 can limit the upper shell 21 and the lower shell 22 to prevent the upper shell 21 and the lower shell 22 from producing radial relative sliding. The inner connecting surface 231 is provided with a threaded hole thereon. The outer connecting surface 232 is provided with a corresponding through hole thereon. The connecting device 23 is provided with a fastening device. The fastening device comprises a plurality of gaskets 234 and inner hexagonal cylindrical head screws 235.
[0030] The inner shell anti-rotation positioning block 25 (see Figure 1 and 2 ) prevents the inner shell 2 from rotating in the inner cavity of the outer shell 1 during pump operation, thereby ensuring normal operation of the pump and prolonging the service life.
[0031] The inner shell circumferential positioning block 26 (see Figure 1 and 2 ) prevents the inner shell 2 from axially displacing and circumferentially moving with the outer cylinder 1. The inner shell circumferential positioning block 26 is arranged on the middle plane of the upper shell 21 and the lower shell 22.
[0032] During normal operation of the pump, the pressure outside the inner shell 2 is greater than the pressure inside the inner shell 2, that is, the inner shell 2 bears external pressure. However, when the outer side of the inner shell 2 is not filled with liquid during pump startup, the internal pressure of the inner shell 2 is greater than the external pressure, and the middle split flange surface of the upper shell 21 and the lower shell 22 may have a gap. In order to prevent this possibility, a limiting mechanism 24 is provided. Figure 4 Fig. 4 is a schematic view of the limiting mechanism in the utility model, Figure 5 Fig. 5 is a schematic view of the cross section of the limiting mechanism in the utility model, Figure 6-1 Fig. 6 is a schematic view of the wedge block structure in the utility model, Figure 6-2 Fig. 7 is a schematic view of the position of the taper angle θ of the wedge block in the utility model. As shown in the above figures: the limiting mechanism 24 is provided with four, and one limiting mechanism 24 is provided in each of the four directions of the middle split surface. Each limiting mechanism 24 comprises one wedge block 241, one trapezoidal groove 243 and two set screws 242. The wedge block 241 is shown in Fig. 6, which has a trapezoidal cross section. The wedge block cap can be circular, triangular, polygonal, etc. The two parallel surfaces of the trapezoidal cross section cut the wedge block cap, so that it remains in the same plane. The wedge block 241 is installed in the trapezoidal groove 243 and is clamped by the set screw 242.
[0033] In the specific implementation process of the utility model, the taper angle θ of the wedge block 241 can be 5-12°. In the specific implementation, the taper angle of the trapezoidal groove 243 and the taper angle θ of the wedge block 241 are the same. The distance between the small end surface of the trapezoidal groove 243 and the small end surface of the wedge block 241 can be 2-5 mm. The distance between the large end surface of the trapezoidal groove 243 and the large end surface of the wedge block 241 is 1 / 3 of the width of the wedge block. The length of the trapezoidal groove is longer than the length of the wedge block by 2-5 mm. The above parameters can be modified to other values or ranges according to specific requirements.
[0034] The assembly and disassembly processes of the utility model are as follows:
[0035] Inner shell assembly process steps:
[0036] 1, the upper shell 21 is combined on the lower shell 22, and the center is adjusted;
[0037] 2, the wedge block 241 is installed in the trapezoidal groove 243, and the wedge block 241 is tightly pressed by the locking screw 242;
[0038] 3, install the gasket 234 and the inner hexagonal cylindrical head screw 235.
[0039] In the process of disassembling, when the upper shell 21 and the lower shell 22 of the inner shell 2 are split, the following steps are carried out:
[0040] 1, first, the locking screw 242 of the wedge block is disassembled;
[0041] 2, then the wedge block 241 is loosened by using a tool, and the wedge block 241 is pulled out by using the tool to clamp the wedge block cap;
[0042] 3, then the inner hexagonal cylindrical head screw 235 and the gasket 234 on the split surface connecting device 23 are disassembled;
[0043] 4, finally, the upper shell 21 is separated from the lower shell 22, and the disassembly of the inner shell 2 is completed.
[0044] In the utility model, the inner shell anti-rotation positioning block 25 is adopted, rotation of the inner shell 2 in the inner cavity of the outer shell 1 during pump operation is prevented, normal operation of the pump is ensured, and service life is prolonged.
[0045] In the utility model, the inner shell circumferential positioning block 26 is adopted, so that the inner shell 2 does not produce axial displacement and circumferential movement with the outer cylinder 1.
[0046] The radial dimension of the inner shell in the utility model is reduced, so that the radial dimension of the whole pump is small, transportation and installation space is reduced, pump body weight is reduced, and cost is reduced. The split surface connecting mode in the utility model reduces the casting difficulty of the split surface of the inner shell.
[0047] The basic principle and main features of the utility model and the advantages of the utility model are shown and described. It should be understood by those skilled in the art that the utility model is not limited by the above examples, and the above examples and descriptions in the specification are only to illustrate the principle of the utility model, and various changes and improvements can be made without departing from the spirit and scope of the utility model. The utility model falls within the scope of the utility model claimed, and the scope of protection of the utility model is defined by the appended claims and their equivalents.
Claims
1. A connection structure with an open face in a double-casing multistage pump, characterized in that: The connecting structure of the double-shell multi-stage pump with open surface comprises an inner shell, an outer cylinder body sleeved outside the inner shell, The outer cylinder body is provided with an inlet flange and an outlet flange, and the outer cylinder body and the pump cover jointly form a sealed cavity to seal the inner shell in the sealed cavity. The rotor component is installed inside the inner shell and jointly forms the flow component of the pump with the transition flow channel of the inner shell. The inner shell comprises an upper shell and a lower shell, and the upper shell and the lower shell are arranged in central symmetry; a middle open flange surface is arranged between the upper shell and the lower shell, and connecting devices are arranged on both sides of the middle open flange surface; one limiting mechanism is arranged at each of the four corners of the middle open surface. An inner shell anti-rotation positioning block is arranged on the high-pressure side end surface of the inner shell, and an inner shell circumferential positioning block is arranged on the middle plane of the upper shell and the lower shell.
2. The double-casing multi-stage pump middle opening surface connecting structure according to claim 1, characterized in that: The connecting device comprises an inner joint surface and an outer joint surface; the inner joint surface and the outer joint surface are in clearance fit, the inner joint surface is provided with a threaded hole thereon, the outer joint surface is provided with a corresponding through hole thereon, and the connecting device is provided with a fastening device, which comprises a plurality of gaskets and inner hexagonal cylindrical head screws.
3. The double-casing multi-stage pump middle open surface connecting structure according to claim 2, characterized in that: Each limiting mechanism comprises a wedge-shaped block, a trapezoidal groove and two sets of set screws; the wedge-shaped block is installed in the trapezoidal groove and is tightly pressed by the set screws.
4. The double-casing multi-stage pump middle open surface connecting structure according to claim 3, characterized in that: The taper angle θ of the wedge-shaped block is 5-12°.
5. The double-casing multi-stage pump middle open surface connecting structure according to claim 4, characterized in that: The taper angle of the trapezoidal groove is the same as the taper angle θ of the wedge-shaped block.
6. The double-casing multi-stage pump middle open surface connecting structure according to claim 5, characterized in that: The distance between the small end surface of the trapezoidal groove and the small end surface of the wedge-shaped block is 2-5mm.
7. The double-casing multi-stage pump middle open surface connecting structure according to claim 3, characterized in that: The distance between the large end surface of the trapezoidal groove and the large end surface of the wedge-shaped block is 1 / 3 of the width of the wedge-shaped block.
8. The double-casing multi-stage pump middle open surface connecting structure according to claim 7, characterized in that: The length of the trapezoidal groove is 2-5mm longer than the length of the wedge-shaped block.