Pump turbine block guide bearing bush supporting structure and method

Abstract

The invention provides a pump turbine block guide bearing bush supporting structure and method, and belongs to the field of pump turbine manufacturing. The problems that an existing guide bearing bush is not smooth in inclination, a supporting piece is prone to abrasion, and an oil wedge on the surface of the bearing bush is poor in bearing are solved. The bearing comprises a bearing body, a wedge-shaped plate, a thrust supporting block, a steering knuckle, a guide bearing bush, a fixing device and a bush seat, the bearing body and the guide bearing bush are arranged in parallel to form a radial space, and a wedge-shaped plate, a thrust supporting block and a steering knuckle are arranged in the radial space; the contact surfaces of the wedge-shaped plate and the bearing body as well as the steering knuckle and the guide bearing bush are vertically matched, the contact surfaces of the wedge-shaped plate and the thrust supporting block are in inclined surface fit, and the contact surfaces of the steering knuckle and the thrust supporting block are in spherical surface fit; and the bearing body is connected with the wedge-shaped plate through a fixing device. The invention effectively solves the problems of unsmooth inclination of the guide bearing bush, easy abrasion of the supporting piece and poor bearing of the oil wedge on the surface of the bearing bush, and improves the bearing capacity of the guide bearing and the operation stability of the pump turbine.

Description

Technical Field

[0001] The present invention relates to the field of manufacturing of pump - turbine, and particularly to a support structure and method for segmental guide bearing pads of a pump - turbine. Background Art

[0002] The operating conditions of a pump - turbine are complex and changeable. The forward and reverse operating modes pose higher requirements for the performance of the guide bearing. In the traditional support structure for segmental guide bearing pads of a pump - turbine, compression blocks and wedge plates with planar contact are arranged between the bearing pads and the bearing body, and a seat structure with a whole - surface contact is arranged below the bearing pads. In this structure, the bearing pads are in planar contact with both the compression blocks and the wedge plates, and have a large contact area with the seat. When the force on the unit changes, the bearing pads are not smooth in tilting, and a self - balancing oil wedge with excellent load - bearing capacity cannot be formed. Moreover, due to the complex operating conditions and large vibration of the pump - turbine, the vibration and swing values of the main shaft and the unit will increase, affecting the performance of the unit.

[0003] In summary, there is an urgent need to design a relatively reliable structure that can improve the tilting flexibility of the guide bearing pads, facilitate the adjustment of the installation clearance between the guide bearing pads and the main shaft collar, and improve the oil - wedge performance of the bearing pad surface. Summary of the Invention

[0004] A brief overview of the present invention is given below to provide a basic understanding of certain aspects of the present invention. It should be understood that this overview is not an exhaustive overview of the present invention. It is not intended to identify the key or important parts of the present invention, nor is it intended to limit the scope of the present invention. Its purpose is merely to present certain concepts in a simplified form as a prelude to the more detailed description to follow.

[0005] In view of this, to solve the problems of unsmooth tilting of the existing guide bearing pads, easy wear of the support members, and poor oil - wedge load - bearing on the bearing pad surface, the present invention provides a support structure and method for segmental guide bearing pads of a pump - turbine.

[0006] Solution 1: A support structure for segmental guide bearing pads of a pump - turbine, comprising a bearing body, a wedge plate, a thrust support block, a knuckle joint, a guide bearing pad, a fixing device, a seat and a second bolt;

[0007] The bearing body and the guide bearing pad are placed in parallel to form a radial space, and a wedge plate, a thrust support block and a knuckle joint are arranged in the radial space;

[0008] The contact surfaces between the wedge plate and the bearing body, and between the knuckle joint and the guide bearing pad are in vertical fit, the contact surface between the wedge plate and the thrust support block is in inclined - plane fit, and the contact surface between the knuckle joint and the thrust support block is in spherical fit;

[0009] The bearing body and the wedge plate are connected by a fixing device, and the fixing device includes a screw, a nut, a pressing plate, a first bolt, and a sleeve; the first bolt fixes the pressing plate on the bearing body, the screw sequentially passes through the pressing plate and the sleeve and is connected to the wedge plate, and the screw is fixed above the pressing plate by two nuts;

[0010] The bearing pad and the bearing body are connected by a second bolt.

[0011] Furthermore, a 1:50 inclined surface fit is adopted between the wedge plate and the thrust support block.

[0012] Furthermore, the distance of the sleeve cutting is calculated according to the installation clearance between the guide bearing pad and the main shaft journal and the 1:50 slope.

[0013] Furthermore, the surfaces of the thrust support block and the knuckle joint have a nitrided layer.

[0014] Solution Two: An installation method for the support structure of the segmented guide bearing pad of a pump-turbine, specifically including the following steps:

[0015] S1. The main shaft journal and the bearing body are installed in place, and the bearing pad is connected to the bearing body by a second bolt;

[0016] S2. One side of the guide bearing pad is pressed against the main shaft journal, and a knuckle joint and a thrust support block are installed on the other side. Then, a wedge plate is installed between the thrust support block and the bearing body;

[0017] S3. The first bolt passes through the pressing plate and is connected to the bearing body. Measure the distance from the upper end face of the wedge plate to the lower end face of the pressing plate, and calculate the distance that the sleeve should be cut according to the installation clearance between the guide bearing pad and the main shaft journal and the 1:50 slope;

[0018] S4. After the sleeve is cut, it is installed between the wedge plate and the pressing plate. The screw sequentially passes through the pressing plate and the sleeve and is connected to the wedge plate. Two nuts are tightened and fixed to the screw above the pressing plate, and the installation is completed.

[0019] The present invention has the following beneficial effects compared with the prior art:

[0020] 1. In the present invention, the bearing pad and the bearing pad adopt non-full-plane contact. The bearing pad relies on the spherical surface fit of the thrust support block and the knuckle joint to reduce the contact surface with the bearing pad, improve the flexibility of the inclination of the guide bearing pad, and facilitate the formation of an excellent oil wedge shape between the guide bearing pad and the main shaft journal;

[0021] 2. In the device of the present invention, the thrust support block and the knuckle joint are small-sized components, and surface processes such as nitriding can be used to improve the surface hardness and extend the service life of the bearing pad support structure;

[0022] 3. The device of the present invention can adjust the installation position of the wedge plate by adjusting the installation height of the screw and cutting the casing accordingly, so as to adjust the installation clearance between the guide bearing pad and the main shaft collar.

[0023] 4. The split guide bearing pad support structure of the device of the present invention enables the guide bearing pad to tilt flexibly according to the forward and reverse rotation of the unit through the spherical support structure during the operation of the pump-turbine, facilitating the formation of an excellent oil wedge shape between the bearing pad surface and the main shaft collar, thereby improving the load-bearing capacity of the guide bearing and the operating stability of the pump-turbine. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The drawings described herein are used to provide a further understanding of the present invention and form a part of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings:

[0025] Figure 1 is a schematic structural diagram of a split guide bearing pad support structure of a pump-turbine;

[0026] Figure 2 is a partial top view of a split guide bearing pad support structure of a pump-turbine;

[0027] Figure 3 is the front view after the installation of the present invention.

[0028] In the figures: 1 - bearing body, 2 - wedge plate, 3 - thrust support block, 4 - knuckle joint, 5 - guide bearing pad, 6 - screw, 7 - nut, 8 - pressing plate, 9 - first bolt, 10 - casing, 11 - pad seat, 12 - second bolt, 13 - main shaft collar. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0029] In order to make the technical solutions and advantages in the embodiments of the present invention clearer and more understandable, the following further details the exemplary embodiments of the present invention with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than an exhaustive list of all embodiments. It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments can be combined with each other.

[0030] Embodiment 1. Refer to Figures 1-3 to illustrate the embodiment method. A split guide bearing pad support structure and method of a pump-turbine include a bearing body 1, a wedge plate 2, a thrust support block 3, a knuckle joint 4, a guide bearing pad 5, a fixing device, a pad seat 11, and a second bolt 12;

[0031] The bearing body 1 and the guide bearing pad 5 are placed parallel to form a radial space, and a wedge plate 2, a thrust support block 3, and a knuckle joint 4 are arranged in the radial space;

[0032] The contact surfaces between the wedge plate 2 and the bearing body 1, between the steering knuckle 4 and the guide bearing bush 5 are all vertically matched. The contact surface between the wedge plate 2 and the thrust support block 3 is inclinedly matched, and the contact surface between the steering knuckle 4 and the thrust support block 3 is spherically matched;

[0033] The bearing body 1 and the wedge plate 2 are connected by a fixing device, and the fixing device includes a screw 6, a nut 7, a pressing plate 8, a first bolt 9, and a sleeve 10. The first bolt 9 fixes the pressing plate 8 on the bearing body 1. The screw 6 passes through the pressing plate 8 and the sleeve 10 in sequence and is connected to the wedge plate 2. The screw 6 is fixed above the pressing plate 8 by two nuts 7;

[0034] The tile seat 11 and the bearing body 1 are connected by a second bolt 12.

[0035] Further, a 1:50 inclined surface fit is adopted between the wedge plate 2 and the thrust support block 3.

[0036] Further, the distance of the sleeve 10 to be cut is calculated according to the installation clearance between the guide bearing bush 5 and the main shaft collar 13 and the 1:50 slope.

[0037] Further, the surfaces of the thrust support block 3 and the steering knuckle 4 have a nitrided layer.

[0038] Embodiment 2. An installation method for a support structure of a split guide bearing bush of a pump-turbine specifically includes the following steps:

[0039] S1. The main shaft collar 13 and the bearing body 1 are installed in place, and the tile seat 11 is connected to the bearing body 1 by a second bolt 12;

[0040] S2. One side of the guide bearing bush 5 is pressed against the main shaft collar 13, and the steering knuckle 4 and the thrust support block 3 are installed on the other side. Then, the wedge plate 2 is installed between the thrust support block 3 and the bearing body 1;

[0041] S3. The first bolt 9 passes through the pressing plate 8 and is connected to the bearing body 1. Measure the distance from the upper end face of the wedge plate 2 to the lower end face of the pressing plate 8, and calculate the distance that the sleeve 10 should be cut according to the installation clearance between the guide bearing bush 5 and the main shaft collar 13 and the 1:50 slope;

[0042] S4. After the sleeve 10 is cut, it is installed between the wedge plate 2 and the pressing plate 8. The screw 6 passes through the pressing plate 8 and the sleeve 10 in sequence and is connected to the wedge plate 2. Two nuts 7 are tightened and fixed to the screw 6 above the pressing plate 8, and the installation is completed.

[0043] Through the present invention, the bearing pad and the pad seat adopt non-full-plane contact. The bearing pad relies on the spherical surface fit of the thrust support block and the knuckle joint to reduce the contact surface with the pad seat, improve the flexibility of the guide bearing pad to tilt, and facilitate the formation of an excellent oil wedge shape between the guide bearing pad and the main shaft journal. At the same time, the thrust support block and the knuckle joint in this device are small-sized components, and surface processes such as nitriding can be used to improve the surface hardness and extend the service life of the bearing pad support structure.

[0044] Through the present invention, when the pump-turbine is in operation, the guide bearing pad can tilt flexibly according to the forward and reverse rotation of the unit through the spherical surface support structure, which is convenient for forming an excellent oil wedge shape between the bearing pad surface and the main shaft journal, thereby improving the load-carrying capacity of the guide bearing and the operation stability of the pump-turbine.

[0045] Although the present invention has been described based on a limited number of embodiments, those skilled in the art in this technical field will understand, based on the above description, that other embodiments can be conceived within the scope of the present invention thus described. In addition, it should be noted that the language used in this specification is mainly selected for readability and teaching purposes, rather than for the purpose of explaining or limiting the subject matter of the present invention. Therefore, many modifications and changes are obvious to those of ordinary skill in this technical field without departing from the scope and spirit of the appended claims. For the scope of the present invention, the disclosure of the present invention is illustrative rather than restrictive, and the scope of the present invention is defined by the appended claims.

Claims

1. A water pump turbine block guide bearing bushing support structure, characterized in that: It comprises a bearing body (1), a wedge plate (2), a thrust support block (3), a steering knuckle (4), a guide bearing bush (5), a fixing device, a bush seat (11) and a second bolt (12); The bearing body (1) and the guide bearing bush (5) are placed in parallel to form a radial space, and a wedge plate (2), a thrust support block (3) and a steering knuckle (4) are arranged in the radial space; The contact surfaces of the wedge plate (2) and the bearing body (1), and the steering knuckle (4) and the guide bearing bush (5) are all vertically matched, the contact surfaces of the wedge plate (2) and the thrust support block (3) are inclinedly matched, and the contact surfaces of the steering knuckle (4) and the thrust support block (3) are spherically matched; The bearing body (1) is connected to the wedge plate (2) via a fixing device, and the fixing device comprises a screw (6), a nut (7), a pressure plate (8), a first bolt (9), and a sleeve (10); the first bolt (9) fixes the pressure plate (8) to the bearing body (1), the screw (6) passes through the pressure plate (8) and the sleeve (10) in sequence to be connected to the wedge plate (2), and the screw (6) is fixed above the pressure plate (8) via two nuts (7); The shoe seat (11) is connected to the bearing body (1) via a second bolt (12).

2. A pump turbine block guide bearing support structure according to claim 1, characterized in that: The wedge plate (2) and the thrust support block (3) are matched with each other in an inclined plane with a ratio of 1:

50.

3. The water pump turbine block guide bearing support structure according to claim 1, characterized in that: The distance of the sleeve (10) is calculated based on the installation clearance between the guide bearing bush (5) and the main shaft collar (13) and the slope of 1:

50.

4. The water pump turbine block guide bearing support structure according to claim 1, characterized in that: The surfaces of the thrust support block (3) and the steering knuckle (4) are provided with a nitriding layer.

5. A method for installing the block guide bearing support structure of a pump turbine according to claim 1, characterized in that: The specific steps include: S1. The spindle collar (13) and the bearing body (1) are installed in place, and the shoe seat (11) is connected to the bearing body (1) through the second bolt (12); S2. Place the guide bearing bush (5) on one side close to the main shaft collar (13), install the steering knuckle (4) and the thrust support block (3) on the other side, and then install the wedge plate (2) between the thrust support block (3) and the bearing body (1); S3. The first bolt (9) passes through the pressure plate (8) and is connected to the bearing body (1). The distance from the upper end surface of the wedge plate (2) to the lower end surface of the pressure plate (8) is measured. The distance that the sleeve (10) should be cut is calculated based on the installation clearance between the guide bearing bush (5) and the main shaft collar (13) and the slope of 1:

50. S4. The sleeve (10) is cut and installed between the wedge plate (2) and the pressure plate (8). The screw (6) passes through the pressure plate (8) and the sleeve (10) in sequence and is connected to the wedge plate (2). Two nuts (7) are tightened and fixed to the screw (6) above the pressure plate (8). The installation is completed.

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