COMBINED BEARING UNIT OF A DYNAMIC PUMPING UNIT

Abstract

This utility model pertains to mechanical engineering, specifically to bearing assemblies for dynamic pumping units that support radial and axial loads acting on the pump shaft. The combined bearing assembly comprises a housing, shaft, radial and thrust plain bearings, a thrust bearing, a heel, a support flange, damping elements, antifriction bushings and washers, a shaft protective sleeve, an intermediate sleeve, and means for securing the elements against rotation and axial displacement. The bearing assembly housing is installed in the pump casing between the flow paths via the intermediate sleeve and is provided with a flange with through holes for fluid flow.The technical result consists in increasing the operational reliability of a combined bearing unit of a dynamic pumping unit when it is placed between the flow parts of the pump due to the structural simplification of the unit and shaft, maintaining the coaxiality of the elements of the radial and thrust plain bearings, damping axial loads and ensuring the passage of fluid flow through the housing of the bearing unit.

Description

[0001] This utility model relates to mechanical engineering, specifically to bearing assemblies of dynamic pumping units designed to support radial and axial loads acting on the pump shaft during operation. The utility model can be used in non-displacement pumps, primarily in centrifugal, multistage centrifugal, and other high-speed pumping units. The assembly is installed in the pump casing between the flow passages and interacts with the pump shaft, ensuring its radial alignment and supporting axial forces. During pump operation, the bearing assembly ensures fluid flow through the casing and the simultaneous operation of the radial and thrust plain bearings.

[0002] The following solutions are known from the prior art.

[0003] A combined pump bearing assembly is known from patent RU 202711 U1, published on March 3, 2021. The known assembly comprises a housing, a shaft supported by radial and thrust plain bearings, a thrust bearing seat, a damping element, a heel housing, a support flange, and fixed and movable antifriction bushings. The protective sleeve is mounted on the shaft journal, and the bearing assembly housing is mounted on the shaft journal and is provided with a flange with blind holes for fixation in the pump casing. A disadvantage of this solution is that the design is oriented toward installation on the shaft journal and does not provide for placement of the bearing assembly housing within the pump casing between the flow paths via an intermediate sleeve with through holes for fluid flow. In addition, the implementation of the unit with a connection to the shaft journal complicates the shaft and limits the application of the solution in cantilever layouts of the pump flow parts.

[0004] A combined pump bearing assembly is known under patent RU 200750 U1, published on November 11, 2020. This known solution comprises a housing mounted on the pump shaft journal, radial and thrust plain bearings, a thrust bearing, a damping element, a heel housing, a support flange, and fixed and movable antifriction bushings. In this solution, the protective sleeve is secured relative to the shaft journal by a clamping nut screwed onto the threaded end of the journal. A disadvantage of this alternative is the complexity of the shaft design and assembly due to the need for a journal, a threaded end, and a clamping nut. Furthermore, this known assembly is not designed for installation between the pump's flow paths, ensuring free fluid flow through the bearing assembly housing.

[0005] A bearing assembly is known from patent RU 2290545 C1, published on December 27, 2006. This solution comprises a housing, shaft, radial bearings, and support sections arranged along the shaft axis, including stops, thrust plain bearings, sliding supports, and elastic elements. This known assembly is designed to withstand increased axial loads and distribute the load between the support elements. A disadvantage of this solution is its design complexity, the presence of multiple support sections, compensators, and adjustment elements, which increases the axial dimensions and makes assembly labor-intensive. Furthermore, this known solution is not intended for compact placement in a pump housing between flow paths with fluid flowing through the bearing assembly.

[0006] The closest analogue to the claimed utility model is the combined pump bearing assembly according to patent RU 202711 U1, since it, like the claimed utility model, comprises a housing, shaft, radial and thrust plain bearings, a thrust bearing, a heel, damping elements, antifriction elements, and anti-rotation locking devices. However, this closest analogue does not provide for the structurally simple placement of the bearing assembly between the pump's flow paths via an intermediate sleeve with through holes for fluid flow and does not eliminate the complexity of the shaft associated with the implementation of the journal and associated mounting sections.

[0007] The objective of the utility model is to create a combined bearing unit for a dynamic pump unit, suitable for installation in a pump casing between flow paths, ensuring the perception of radial and axial loads with a simplified design of the unit and pump shaft.

[0008] The technical result of the utility model consists in increasing the operational reliability of the combined bearing unit of a dynamic pumping unit when it is placed between the flow parts of the pump by means of a structural simplification of the unit and shaft, maintaining the coaxiality of the elements of the radial and thrust plain bearings, damping axial loads and ensuring the passage of fluid flow through the housing of the bearing unit.

[0009] The specified technical result is uniform for the entire set of features of the utility model, since each of the features is aimed at ensuring a stable position of the shaft, the perception of radial and axial loads, reducing distortions and wear of antifriction elements, simplifying the fixation of parts and the ability of the unit to operate in a liquid flow inside the pump unit.

[0010] This problem is solved by a combined bearing assembly of a dynamic pump unit comprising a housing through which a shaft passes, supported by radial and thrust plain bearings. The thrust bearing's center bearing is secured against rotation relative to the bearing assembly housing and mounted on a damping element located between the bearing assembly housing and the center bearing housing, which contains an antifriction washer.

[0011] The thrust bearing seat is secured against rotation relative to the bearing housing by flats machined in the housing and grooves machined in the seat. The bearing housing is installed in the pump casing between the flow paths via an intermediate sleeve and is designed with a flange containing through-holes for fluid flow. This allows the bearing assembly to be positioned not only at the end of the shaft but also between the pump's flow paths without blocking fluid flow.

[0012] The bearing housing is installed against the support flange via a damping element located between them. The bearing housing is secured against rotation relative to the support flange by flats machined in the support flange and grooves machined in the bearing housing. The support flange is mounted on the shaft and secured axially by a cylindrical thrust ring and against rotation by a key. This design eliminates the need for complex shaft machining to accommodate the journal and ensures stable positioning of the thrust bearing components when supporting axial loads.

[0013] The radial bearing is installed in the bearing housing. The stationary antifriction sleeve of the radial bearing is placed in a protective casing and secured in the bearing housing by crimping, which clamps the stationary antifriction sleeve and protective casing within the bearing housing. The stationary antifriction sleeve encloses a movable antifriction sleeve mounted on the protective sleeve of the pump shaft. The protective sleeve is secured against rotation relative to the shaft by a key and is limited from axial displacement by spring retaining rings installed in annular grooves made on the shaft. A thrust sleeve is installed between one of the spring retaining rings and the support flange to press the support flange against the cylindrical thrust ring.

[0014] In a particular embodiment, a channel is made along the length of the shaft for supplying a lubricating medium into the space between the antifriction washers of the thrust bearing, while the channel is connected to the said space by radial holes with a diameter of 3-4 mm.

[0015] Anti-friction washers and anti-friction bushings are made of an anti-friction material suitable for use in sliding contact conditions and the impact of a lubricant and / or the pumped fluid. The damping elements are made of a material capable of absorbing and damping axial shock and pulsating loads. The pumped fluid passes through through holes in the bearing housing flange, and the lubricant acts as a medium, reducing friction between the anti-friction washers of the thrust bearing.

[0016] The design of the bearing unit housing with the possibility of installation in the pump housing between the flow parts through an intermediate sleeve ensures the placement of the unit inside the pump unit without increasing the axial dimensions, which helps to increase the reliability of the unit in cantilever arrangements of the pump flow parts.

[0017] The creation of through holes in the housing flange for the passage of liquid flow prevents the blocking of the flow part of the pump unit, reduces the hydraulic resistance in the area of ​​​​the bearing unit installation and allows the unit to be used in the working area of ​​​​the liquid passage.

[0018] The placement of the shaft in both radial and thrust plain bearings ensures the absorption of both radial and axial loads, which reduces the likelihood of shaft distortion and uneven wear of the antifriction surfaces.

[0019] The fixation of the thrust bearing from rotation by means of chamfers in the housing and grooves in the thrust bearing prevents the rotation of the fixed element of the thrust bearing, which stabilizes the contact of the antifriction washers and increases the reliability of the unit.

[0020] Installing the thrust bearing on the damping element smooths out axial pulsating loads, reduces the impact on the anti-friction washers and decreases the risk of their accelerated wear.

[0021] Installing the heel body with a stop in the support flange through the damping element ensures damping of the axial load from the rotating unit and promotes uniform load absorption by the thrust plain bearing.

[0022] Fixing the heel housing from turning relative to the support flange by means of chamfers and grooves prevents disruption of the relative position of the thrust bearing elements and reduces the likelihood of scuffing and distortion of the antifriction surfaces.

[0023] The fixation of the support flange from rotation with a key and in the axial direction with a cylindrical thrust ring ensures a stable position of the support flange on the shaft without using a threaded clamping nut on the journal, which simplifies the shaft and reduces the likelihood of loosening of threaded connections during vibrations.

[0024] The placement of the fixed anti-friction sleeve in a protective casing protects the sleeve during installation and operation, and also ensures its stable position in the bearing assembly housing.

[0025] Fixing the fixed anti-friction bushing with the casing by rolling eliminates the need for additional fasteners, simplifies assembly and reduces the risk of fasteners loosening or coming loose due to vibration.

[0026] The fixed anti-friction sleeve covers the movable anti-friction sleeve, ensuring radial centering of the shaft and maintaining the coaxiality of the thrust bearing elements, which reduces distortion and increases the reliability of the unit.

[0027] Installing a sliding anti-friction sleeve on the shaft protective sleeve protects the shaft from wear in the radial bearing area and simplifies the replacement of the wearing element without replacing the shaft.

[0028] The protective sleeve is secured against rotation with a key, which ensures that rotation is transmitted without the protective sleeve slipping relative to the shaft, which prevents wear on the mounting surfaces.

[0029] The protective sleeve is limited from axial displacement by spring retaining rings installed in the annular grooves of the shaft, providing simple and reliable axial fixation without threaded elements, which simplifies assembly and maintenance.

[0030] Installing a thrust sleeve between the snap ring and the support flange ensures that the support flange is pressed against the cylindrical thrust ring and stabilizes the axial position of the thrust bearing elements.

[0031] The creation of a channel along the length of the shaft and radial holes with a diameter of 3-4 mm for supplying the lubricating medium to the antifriction washers ensures that the lubricant is supplied directly to the friction zone without additional external pipelines, which reduces the design complexity and increases the reliability of lubrication.

[0032] The solution is further explained with references to figures showing the following.

[0033] Fig. 1 - combined bearing unit of a dynamic pump unit in longitudinal section.

[0034] Fig. 2 - section A-A from Fig. 1, illustrates the location of the flange part of the bearing unit housing, through holes for the passage of fluid flow, as well as elements for fixing the heel housing relative to the support flange.

[0035] Fig. 3 - section B-B from Fig. 1, section B-B illustrates the interaction of the flats of the bearing assembly housing and the grooves of the thrust bearing, ensuring the fixation of the thrust bearing from turning.

[0036] The following items are indicated by the positions on the drawings:

[0037] 1 - bearing unit housing;

[0038] 2 - shaft;

[0039] 3 - thrust bearing seat;

[0040] 4 - damping element of the heel pad;

[0041] 5 - anti-friction washer of the thrust bearing;

[0042] 6 - chamfers in the bearing housing;

[0043] 7 - grooves in the heel;

[0044] 8 - pump body;

[0045] 9 - intermediate sleeve;

[0046] 10 - through holes for liquid flow;

[0047] 11 - heel body;

[0048] 12 - support flange;

[0049] 13 - damping element between the heel body and the support flange;

[0050] 14 - chamfers in the support flange;

[0051] 15 - grooves in the heel body;

[0052] 16 - cylindrical thrust ring;

[0053] 17 - support flange key;

[0054] 18 - fixed antifriction sleeve of radial bearing;

[0055] 19 - protective cover of fixed antifriction bushing;

[0056] 20 - movable antifriction sleeve of radial bearing;

[0057] 21 - shaft protective sleeve;

[0058] 22 - protective sleeve key;

[0059] 23 - spring retaining rings;

[0060] 24 - thrust sleeve;

[0061] 25 - channel for supplying lubricating medium;

[0062] 26 - radial holes for draining the lubricant to the antifriction washers.

[0063] Detailed description of the utility model

[0064] The combined bearing unit of the dynamic pump unit comprises a housing 1 through which a shaft 2 passes. Shaft 2 is placed in a radial plain bearing and a thrust plain bearing, due to which one unit bears the radial load associated with the rotation of the shaft and the action of the pump impellers, and the axial load arising from the operation of the flow parts of the pump unit.

[0065] Thrust bearing seat 3 is installed in housing 1 and interacts with antifriction washer 5. Between housing 1 and thrust bearing seat 3, there is damping element 4. Damping element 4 absorbs part of the axial pulsations and reduces the impact effect on antifriction washer 5. Thrust bearing seat 3 is fixed from rotation relative to housing 1 by means of chamfers 6 made in housing 1 and grooves 7 made in thrust bearing seat 3.

[0066] Bearing assembly housing 1 is installed in pump housing 8 via intermediate sleeve 9. Intermediate sleeve 9 secures housing 1 within pump housing 8 and allows the bearing assembly to be positioned between the pump unit's flow paths. Through holes 10 are provided in the flanged portion of housing 1, allowing fluid flow. This design allows the bearing assembly to be integrated into the flow path without completely blocking the flow.

[0067] The body of the heel 11 is installed with an abutment against the support flange 12. Between the body of the heel 11 and the support flange 12, a damping element 13 is located. The body of the heel 11 is fixed from rotation relative to the support flange 12 by means of chamfers 14 made in the support flange 12 and grooves 15 made in the body of the heel 11. This design ensures a stable mutual arrangement of the antifriction surfaces of the thrust bearing when the axial load changes.

[0068] The support flange 12 is mounted on the shaft 2. The support flange 12 is secured against axial displacement by a cylindrical thrust ring 16, and against rotation relative to the shaft 2 by a key 17. Due to this, the support flange 12 is held on the shaft 2 without the need for a complex journal with a threaded end and without the use of a clamping nut, which simplifies the shaft and the assembly of the bearing unit.

[0069] The radial plain bearing is installed in housing 1 of the bearing assembly. The fixed antifriction sleeve 18 is housed in a protective casing 19. The fixed antifriction sleeve 18, together with the protective casing 19, is secured in housing 1 by crimping. The crimping ensures that the sleeve 18 and casing 19 are clamped in housing 1 without the use of additional fasteners.

[0070] The fixed antifriction sleeve 18 encloses the movable antifriction sleeve 20. The movable antifriction sleeve 20 is mounted on the protective sleeve 21 of the shaft 2. The protective sleeve 21 is secured from rotation relative to the shaft 2 by means of a key 22. The protective sleeve 21 is limited from axial displacement by spring retaining rings 23 installed in annular grooves made on the shaft 2.

[0071] A thrust sleeve 24 is installed between one of the spring retaining rings 23 and the support flange 12. The thrust sleeve 24 ensures that the support flange 12 is pressed against the cylindrical thrust ring 16, stabilizing the axial position of the support flange 12 and the heel body 11.

[0072] A channel 25 for supplying lubricant is formed along the length of shaft 2. Channel 25 communicates with the space between the thrust bearing's antifriction washers via radial holes 26. In a specific embodiment, radial holes 26 have a diameter of 3-4 mm. Supplying lubricant through shaft 2 ensures lubrication of the thrust bearing's friction zone without the need for additional external piping.

[0073] Anti-friction washers and anti-friction bushings can be made of an anti-friction material suitable for sliding and contact with the lubricant and / or pumped liquid, such as SiC ceramics, graphite-filled fluoroplastics, or VK6 hard alloy. Damping elements 4 and 13 can be made of a material that provides elastic absorption of axial pulsating loads, such as rubber, fluoroplastic, or a set of stainless steel plates.

[0074] Implementation of a utility model

[0075] Before assembly, support flange 12 is installed on shaft 2, fixed from rotation by key 17 and in the axial direction by cylindrical thrust ring 16. Then, heel body 11 with damping element 13 is installed so that grooves 15 of heel body 11 interact with flats 14 of support flange 12. Next, protective sleeve 21 with movable antifriction sleeve 20 is installed, protective sleeve 21 is fixed from rotation by key 22 and its axial displacement is limited by spring retaining rings 23. Thrust sleeve 24 is installed between spring retaining ring 23 and support flange 12 to press support flange 12 against cylindrical thrust ring 16.

[0076] A thrust bearing 3 with an antifriction washer 5 and a damping element 4 is installed in the housing 1 of the bearing unit. The thrust bearing 3 is oriented so that the grooves 7 of the thrust bearing 3 interact with the flats 6 of the housing 1. The stationary antifriction sleeve 18 is placed in the protective casing 19 and fixed in the housing 1 by crimping. After assembly, the housing 1 is installed in the pump housing 8 through the intermediate sleeve 9 so that the through holes 10 ensure the passage of fluid flow between the flow parts of the pump.

[0077] When shaft 2 of the pump unit rotates, the axial load is supported by the antifriction washers of the heel 11 and the thrust bearing 5, and simultaneously by the damping elements 4 and 13. This ensures uniform load absorption by the antifriction washers of the thrust plain bearing over the maximum possible sliding area relative to each other. At the same time, the radial bearing ensures precise alignment of the antifriction washers of the heel 11 and the thrust bearing 5, and rotation of the pump unit shaft without disturbing the alignment of its impellers relative to the fixed structural elements of the pump unit. Damping elements 4 and 13 smooth out axial pulsations and impact loads. Lubricant is supplied through channel 25 and enters the space between the antifriction washers through radial holes 26, reducing friction and wear.The flow of pumped liquid passes through through holes 10 in the flange of the housing 1, therefore the installation of a bearing unit between the flow parts of the pump does not interfere with the operation of the pump unit.

[0078] This utility model can be used in multistage centrifugal pumping units, high-speed pumping units, pumps with overhung flow paths, and other dynamic pumping units in which the shaft experiences combined radial and axial loads. For example, the unit can be used as an intermediate shaft support between the flow paths of a multistage centrifugal pump. In another example, the unit can be used in a overhung pumping unit, where it is necessary to reduce axial dimensions and simplify the shaft without compromising the axial load capacity.

Claims

1. A combined bearing unit of a dynamic pump unit comprising a housing through which a shaft passes, placed in radial and thrust plain bearings, wherein the thrust bearing seat is fixed against rotation relative to the bearing unit housing and is mounted on a damping element located between the bearing unit housing and the housing of the thrust bearing with an antifriction washer, characterized in that the housing of the bearing unit is installed in the pump housing between the flow parts through an intermediate sleeve and is made with a flange in which through holes are made for the passage of a liquid flow, the housing of the heel is installed with an emphasis against the support flange through a damping element located between them and is fixed against rotation relative to the support flange by means of chamfers made in the support flange and grooves made in the housing of the heel, wherein the support flange is mounted on the shaft and fixed in the axial direction by a cylindrical thrust ring,and from rotation relative to the shaft - by means of a key, the radial bearing is installed in the housing of the bearing unit, while its stationary antifriction sleeve is placed in a protective casing and fixed in the housing of the bearing unit by means of rolling, by means of which the stationary antifriction sleeve with a protective casing is clamped in the housing of the bearing unit, the stationary antifriction sleeve covers a movable antifriction sleeve installed on the protective sleeve of the pump shaft, the protective sleeve is fixed from rotation relative to the shaft by means of a key, and is limited from axial displacement by spring retaining rings installed in annular grooves made on the shaft, while between one of the spring retaining rings and the support flange a thrust sleeve is installed for pressing the support flange to the cylindrical thrust ring.

2. The unit according to paragraph 1, characterized in that a channel is made along the length of the shaft for supplying a lubricating medium into the space between the antifriction washers of the thrust bearing, wherein the channel is connected to the said space by radial holes with a diameter of 3-4 mm.

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