A hydraulic turbine unit and a main shaft axial thrust load reduction device thereof

Abstract

The utility model discloses a water turbine unit and its main shaft axial thrust load reduction device relates to water turbine technical field, and main shaft axial thrust load reduction device includes: support, its near water turbine's main shaft end part setting, magnetically permeable body, its be located in the end of main shaft, electromagnet, its be located on the support, and electromagnet and magnetically permeable body alignment distribution, field winding, its be located in electromagnet, control device, with field winding electricity is connected, and control device is used for controlling the current of field winding to make electromagnet produce required magnetic force, and magnetic force is used for reducing the axial water thrust that thrust pad bears. The device can effectively solve the problem of the temperature rise of thrust pad, the deterioration lubrication condition caused by the excessive axial water thrust, and further cause the fatigue damage of thrust bearing parts (such as thrust pad, elastic oil tank, mirror plate) etc.

Description

Technical Field

[0001] This utility model relates to the field of water turbine technology, and more specifically, to a main shaft axial thrust reduction device. Furthermore, it also relates to a water turbine unit including the aforementioned main shaft axial thrust reduction device. Background Technology

[0002] In existing technologies, during the operation of horizontal turbine units in hydropower stations, the water flow, when passing through the runner, generates a force (i.e., axial water thrust) along the unit's axis (horizontal direction) due to factors such as changes in water flow direction, uneven pressure distribution, or momentum exchange. Axial water thrust has a significant impact on the safe and stable operation of the unit, component lifespan, and efficiency. For example, when the axial water thrust is too large, the load on the thrust bearing will far exceed the design value. The oil film between the thrust bearing pad and the mirror plate may be damaged due to excessive pressure, leading to direct metal-to-metal contact and increased thrust bearing pad temperature. Increased thrust bearing pad temperature leads to decreased lubricant performance (such as reduced viscosity and accelerated oxidation), further deteriorating lubrication conditions and shortening lifespan. Long-term overload can cause fatigue damage to thrust bearing components (such as the thrust bearing pad, elastic oil tank, and mirror plate), significantly shortening their service life and increasing maintenance frequency and costs.

[0003] In summary, how to effectively solve the problems of increased thrust bearing temperature, deteriorated lubrication conditions, and fatigue damage to thrust bearing components caused by excessive axial water thrust is a problem that urgently needs to be solved by those skilled in the art. Utility Model Content

[0004] In view of this, the purpose of this utility model is to provide a spindle axial thrust reduction device, which can effectively solve the problems of excessive axial water thrust causing the thrust bearing temperature to rise, the lubrication conditions to deteriorate, and the resulting fatigue damage to thrust bearing components (such as thrust bearings, elastic oil tanks, and mirror plates).

[0005] Another objective of this invention is to provide a turbine unit that includes the aforementioned main shaft axial thrust reduction device.

[0006] To achieve the above objectives, this utility model provides the following technical solution:

[0007] A spindle axial thrust reduction device, comprising:

[0008] The support frame is installed near the end of the turbine's main shaft.

[0009] A magnetic conductor is disposed at the end of the main shaft;

[0010] An electromagnet is disposed on the support, and the electromagnet and the magnetic conductor are aligned and distributed.

[0011] An excitation winding is disposed within the electromagnet body;

[0012] A control device electrically connected to the excitation winding is provided to control the current in the excitation winding so that the electromagnet generates the required magnetic force, which is used to reduce the axial water thrust borne by the thrust bearing.

[0013] In one embodiment, the magnetic conductor is fixed to the end of the spindle by a first fixing bolt.

[0014] In one embodiment, a mounting flange for fixing the electromagnet to the bracket is further included, the mounting flange being fixed to the bracket by a second fixing bolt.

[0015] In one embodiment, the electromagnet is fixed to the mounting flange by a third fixing bolt.

[0016] In one embodiment, the excitation winding is sealed within the electromagnet body using insulating adhesive.

[0017] In one embodiment, the electromagnet and the excitation winding are coaxially arranged.

[0018] In one embodiment, the bracket includes a base plate that is attached to the ground, a frame that is vertically mounted on the base plate, and reinforcing ribs. The electromagnet is vertically mounted on the frame, and the reinforcing ribs are located on opposite sides of the frame and are vertically mounted on the base plate.

[0019] In one embodiment, the base plate is provided with at least four anchor bolts along the circumferential direction, the anchor bolts being used to fix the base plate to the ground.

[0020] In one embodiment, a detection device is further included for detecting the axial water thrust borne by the thrust bearing, the detection device being connected to the control device.

[0021] A turbine unit includes the axial thrust reduction device for the main shaft as described in any one of the above claims.

[0022] When using the axial thrust reduction device for the main shaft provided by this utility model, during the operation of the turbine, when the water flows through the turbine runner, due to factors such as changes in water flow direction, uneven pressure distribution, or momentum exchange, the force generated on the runner along the unit axis (horizontal direction) is generated, i.e., axial water thrust. The axial water thrust is applied to the thrust bearing by the mirror plate and then transmitted to the main shaft. At this time, the control device can control the current of the excitation winding to make the electromagnet generate the required magnetic force. The magnetic force acts on the magnetic conductor fixed to the main shaft, and the magnetic force is opposite to the axial water thrust, so as to reduce the axial water thrust borne by the thrust bearing, thereby making the main shaft run more smoothly and avoiding the turbine from being overloaded by the excessive axial water thrust, which would cause the oil film between the thrust bearing and the mirror plate to be destroyed due to excessive pressure, resulting in direct metal contact and increased thrust bearing temperature. Increased thrust bearing temperature will lead to decreased lubricating oil performance, deteriorate lubrication conditions, shorten component life, and long-term overload will cause fatigue damage to thrust bearing components (such as thrust bearing, elastic oil tank, mirror plate), significantly shortening the service life of thrust bearing components, leading to a sharp increase in maintenance frequency and maintenance costs. In other words, this device can effectively reduce the various problems caused by excessive axial water thrust.

[0023] In summary, the axial thrust reduction device for the main shaft provided by this utility model can effectively solve the problems of increased thrust bearing temperature and deteriorated lubrication conditions caused by excessive axial water thrust, which in turn leads to fatigue damage in thrust bearing components (such as thrust bearings, elastic oil tanks, and mirror plates). Furthermore, this utility model also provides a turbine unit including the aforementioned axial thrust reduction device for the main shaft. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0025] Figure 1 This is a side cross-sectional view of the spindle axial thrust reduction device provided by this utility model.

[0026] Figure 2 A schematic diagram of the main shaft axial thrust reduction device;

[0027] Figure 3 for Figure 2 The main view;

[0028] Figure 4 for Figure 2 Rear view.

[0029] Figures 1-4 middle:

[0030] 1 is the bracket, 11 is the base plate, 12 is the frame, 13 is the reinforcing rib, 14 is the anchor bolt, 2 is the magnetic conductor, 3 is the electromagnet, 4 is the excitation winding, 5 is the first fixing bolt, 6 is the mounting flange, 7 is the second fixing bolt, and 8 is the third fixing bolt. Detailed Implementation

[0031] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0032] The core of this invention is to provide a main shaft axial thrust reduction device, which can effectively solve the problems of increased thrust bearing temperature and deteriorated lubrication conditions caused by excessive axial water thrust, leading to fatigue damage in thrust bearing components (such as thrust bearings, elastic oil tanks, and mirror plates). Another core aspect of this invention is to provide a turbine unit including the aforementioned main shaft axial thrust reduction device.

[0033] Please refer to Figure 1 This specific embodiment provides a spindle axial thrust reduction device, including:

[0034] Support 1 is installed near the end of the main shaft of the water turbine;

[0035] Magnetic conductor 2, which is located at the end of the main shaft;

[0036] Electromagnet 3 is mounted on support 1, and electromagnet 3 and magnetic conductor 2 are aligned and distributed.

[0037] Excitation winding 4 is located inside electromagnet 3;

[0038] The control device is electrically connected to the excitation winding 4. The control device is used to control the current of the excitation winding 4 so that the electromagnet 3 generates the required magnetic force. The magnetic force is used to reduce the axial water thrust borne by the thrust bearing.

[0039] It should be noted that the excitation winding 4 is a coil winding capable of generating a magnetic field, typically made of wire. When current flows through the excitation winding 4, it generates a magnetic field. The strength of this magnetic field depends on the number of turns of the excitation winding 4, the magnitude of the current, and the geometry of the winding. The electromagnet 3 refers to a device capable of generating a strong magnetic field when energized, usually consisting of the excitation winding 4 wound around an iron core. This iron core is part of the electromagnet 3, and the magnetic field strength of the electromagnet 3 can be adjusted by changing the current in the excitation winding 4. The magnetic conductor 2 is typically a material with high permeability, such as iron or other ferromagnetic materials, which can guide and concentrate the magnetic field, making it more effective in a specific area. In generators or motors, the magnetic conductor 2 can be part of the rotor, working in conjunction with the excitation winding 4 to ensure that the magnetic field can effectively pass through the air gap and act on the other side.

[0040] It should also be noted that the following steps are involved in the coordinated operation of the excitation winding 4, the electromagnet 3, and the magnetic conductor 2: the excitation winding 4 generates a magnetic field after being energized; due to the presence of the electromagnet 3, the magnetic field generated by the excitation winding 4 is enhanced, and the magnetic field generated by the excitation winding 4 acts on the magnetic conductor 2, which is located at the end of the main shaft and can rotate synchronously with the main shaft. Moreover, the electromagnet 3 does not need to directly contact the magnetic conductor 2, and will not hinder the rotation of the magnetic conductor 2 and the main shaft. Furthermore, the magnetic force generated by the coordination of the excitation winding 4 and the electromagnet 3 can reduce the axial water thrust borne by the thrust bearing, which helps to avoid various problems caused by excessive axial water thrust.

[0041] For example, a support 1 can be installed on the ground near the tail end of the turbine's main shaft. This device adds a magnetic force of about 7 tons to the tail end of the main shaft, which is opposite to the axial water thrust. This reduces the original 12-ton axial water thrust on the main shaft, reducing the load on the thrust bearing (i.e., the axial water thrust) to less than 50% of the original. As the axial water thrust decreases, its heat generation also decreases, and the temperature of the thrust bearing will decrease accordingly.

[0042] In practical applications, the shape, structure, size, and position of the support 1, magnetic conductor 2, electromagnet 3, excitation winding 4, and control device can be determined according to the actual situation and needs.

[0043] When using the axial thrust reduction device for the main shaft provided by this utility model, during the operation of the turbine, when the water flows through the turbine runner, due to factors such as changes in water flow direction, uneven pressure distribution, or momentum exchange, the force generated on the runner along the unit axis (horizontal direction) is generated, i.e., axial water thrust. The axial water thrust is applied to the thrust bearing by the mirror plate and then transmitted to the main shaft. At this time, the control device can control the current of the excitation winding 4 to make the electromagnet 3 generate the required magnetic force. The magnetic force acts on the magnetic conductor 2 fixed to the main shaft, and the magnetic force and the axial water thrust are opposite in direction to reduce the axial water thrust borne by the thrust bearing, thereby making the main shaft run more smoothly and avoiding the turbine from being overloaded by the excessive axial water thrust, which would cause the oil film between the thrust bearing and the mirror plate to be destroyed due to excessive pressure, resulting in direct metal contact and increased thrust bearing temperature. Increased thrust bearing temperature will lead to decreased lubricating oil performance, deterioration of lubrication conditions, and shortening of component life. Furthermore, long-term overload will cause fatigue damage to thrust bearing components (such as thrust bearing, elastic oil tank, mirror plate), significantly shortening the service life of thrust bearing components and leading to a sharp increase in maintenance frequency and maintenance costs. In other words, this device can effectively reduce the various problems caused by excessive axial water thrust.

[0044] In summary, the spindle axial thrust reduction device provided by this utility model can effectively solve the problems of increased thrust bearing temperature and deteriorated lubrication conditions caused by excessive axial water thrust, which in turn leads to fatigue damage in thrust bearing components (such as thrust bearings, elastic oil tanks, and mirror plates).

[0045] In one embodiment, the magnetic conductor 2 is fixed to the end of the main shaft by the first fixing bolt 5, so that the magnetic conductor 2 is firmly set at the end of the main shaft. This does not affect the normal operation of the turbine and its main shaft, and can cooperate with the excitation winding 4 and the electromagnet 3 to reduce the axial water thrust borne by the thrust bearing.

[0046] In one embodiment, a mounting flange 6 is further included for fixing the electromagnet 3 to the bracket 1. The mounting flange 6 is fixed to the bracket 1 by a second fixing bolt 7, so as to effectively fix the electromagnet 3 through the mounting flange 6. Both the electromagnet 3 and the magnetic conductor 2 are cylindrical structures, and the central axes of the electromagnet 3 and the magnetic conductor 2 are aligned with the central axis of the main shaft.

[0047] In one embodiment, the electromagnet 3 is fixed to the mounting flange 6 by a third fixing bolt 8. That is, the electromagnet 3 is detachably mounted on the bracket 1. If the electromagnet 3 is damaged, it can be replaced by disassembly, and the new electromagnet 3 and the magnetic conductor 2 can continue to be used together, thereby reducing the maintenance cost of the device and increasing the service life of the device.

[0048] In one embodiment, the excitation winding 4 is sealed inside the electromagnet 3 with insulating adhesive.

[0049] It should be noted that the insulating adhesive effectively blocks current leakage between the excitation winding 4 and the electromagnet 3, preventing short circuits or grounding faults. Furthermore, the sealant fills the gap between the excitation winding 4 and the electromagnet 3, forming an integral structure and enhancing mechanical stability. This not only reduces wire loosening or wear caused by vibration but also resists mechanical shocks during transportation or operation. Moreover, sealing the excitation winding 4 with insulating adhesive reduces faults caused by environmental factors or mechanical fatigue (such as short circuits and insulation aging), thereby reducing maintenance frequency.

[0050] In one embodiment, the electromagnet 3 and the excitation winding 4 are coaxially arranged. That is, the excitation winding 4 can be configured as a ring structure arranged along the central axis of the electromagnet 3. In practical applications, the number and position of the excitation winding 4 can be determined according to actual conditions and requirements.

[0051] In one embodiment, such as Figure 2 As shown, the support 1 includes a base plate 11 that is attached to the ground, a frame 12 that is vertically mounted on the base plate 11, and reinforcing ribs 13. The electromagnet 3 is vertically mounted on the frame 12, and the reinforcing ribs 13 are located on opposite sides of the frame 12 and are vertically mounted on the base plate 11. The reinforcing ribs 13 can strengthen the connection between the frame 12 and the base plate 11 and improve the structural stability of the support 1.

[0052] In one embodiment, the base plate 11 is provided with at least four anchor bolts 14 along the circumference, the anchor bolts 14 being used to fix the base plate 11 to the ground.

[0053] It should be noted that anchor bolts 14 are used to securely fix mechanical equipment or steel structures to the concrete foundation (i.e., the ground), preventing displacement or collapse caused by external factors (such as earthquakes or storms). Furthermore, anchor bolts 14 transfer the load borne by the equipment or structure to the foundation, ensuring the safety of the foundation and structure. High-quality anchor bolts 14 are manufactured from high-strength materials and undergo anti-corrosion treatment, enabling them to maintain a long service life in harsh environments. In addition, the design of anchor bolts 14 helps reduce the risk of loosening due to vibration, thereby improving the seismic resistance and service life of the entire building system.

[0054] In practical applications, the position, number, and type of anchor bolts 14 can be determined according to the actual situation and needs.

[0055] In one embodiment, a detection device for detecting the axial water thrust borne by the thrust bearing is also included, and the detection device is connected to the control device.

[0056] It should be noted that when this device is not in operation, the main shaft of the turbine will be subjected to axial water thrust during operation. When the control device controls the current of the excitation winding 4, the electromagnet 3 generates a suitable magnetic force. The magnetic force of the electromagnet 3 acts on the magnetic conductor 2 and is transmitted to the main shaft to reduce the axial water thrust on the thrust bearing, so that the main shaft runs more smoothly. This avoids the turbine unit from being overloaded by the thrust bearing due to excessive axial water thrust, which could cause the oil film between the thrust bearing and the mirror plate to be damaged due to excessive pressure, resulting in direct metal-to-metal contact and increased thrust bearing temperature. Increased thrust bearing temperature will reduce the performance of the lubricating oil (such as reduced viscosity and accelerated oxidation), further deteriorating lubrication conditions and shortening its life. In addition, long-term overload will cause fatigue damage to thrust bearing components (such as thrust bearing, elastic oil tank, mirror plate), significantly shortening their service life and increasing maintenance frequency and cost.

[0057] To further illustrate the spindle axial thrust reduction device provided by this utility model, examples can be provided.

[0058] 1. Install the fixed bracket 1, such as Figure 1 As shown, the tail end of the turbine's main shaft has the installation space for this device. This device is set on the ground at the tail end of the main shaft. Before fixing the bracket 1, the device can be positioned first, and then the anchor bolts 14 can be pre-embedded by drilling holes. For example, the anchor bolts 14 are M27*300 anchors, and there are 8 of them. They are made of high-strength concrete. After the anchor bolts 14 are installed, the bracket 1 is connected to the fixed base of the turbine unit through channel steel to ensure that the base plate 11 of the bracket 1 does not deform significantly when subjected to force.

[0059] 2. Install electromagnet 3 and magnetic conductor 2, such as Figure 2 and Figure 3 As shown, the magnetic conductor 2 replaces the original end cap and is fixed on the main shaft. The magnetic conductor 2 will rotate synchronously with the main shaft. For example, the four first fixing bolts 5 (such as M24 8.8 grade bolts) can withstand a tensile force of more than 50 tons, which is sufficient to withstand a magnetic force of 7 tons. The electromagnet 3 is installed on the bracket 1. By manually fine-tuning the electromagnet 3 and the magnetic conductor 2, the coaxiality and flatness of the electromagnet 3 and the magnetic conductor 2 are ensured to reach the optimal state.

[0060] 3. Magnetic field simulation: After the excitation winding 4 is loaded with the rated working current, the excitation winding 4 and the electromagnet 3 generate a magnetic field, which generates a magnetic force of 7 tons on the rotating magnetic conductor 2 (which is opposite to the direction of the axial water thrust).

[0061] 4. Install detection devices (such as eddy current displacement sensors). Eddy current displacement sensors are used to detect the axial displacement of the main shaft (which is closely related to the axial water thrust). A displacement sensor can also be added to the guide vane servo (the larger the opening of the guide vane servo of the turbine, the larger the water flow, and the smaller the opening, the smaller the water flow) to detect the opening of the guide vane servo. The signal is transmitted to the control device, which can coordinate the control according to the operating conditions of the turbine unit.

[0062] 5. The control device adopts a PLC (Programmable Logic Controller) + IGBT (Insulated Gate Bipolar Transistor) control mode. This PLC+IGBT control mode is an industrial automation technology solution that combines the intelligent program control of a programmable logic controller with the high-efficiency power switching characteristics of an IGBT. Its core is to drive the IGBT through the PLC output control signal to achieve precise adjustment of high-power loads. For example, using a 24V, 500W DC power supply, by detecting the axial displacement of the main shaft and the opening of the guide vane servo, the control device calculates the corresponding PWM signal through relevant programs and outputs the corresponding current to the excitation winding 4 via the IGBT. The excitation winding 4 and the electromagnet 3 generate a suitable magnetic attraction force to reduce the pressure on the thrust bearing, thereby reducing the heat generated by the thrust bearing, lowering its temperature, reducing unit vibration, and making the operation more stable.

[0063] In addition to the aforementioned main shaft axial thrust reduction device, this utility model also provides a turbine unit that includes the main shaft axial thrust reduction device disclosed in the above embodiments. For the structure of other parts of the turbine unit, please refer to the prior art, which will not be repeated here.

[0064] It should be noted that the first fixing bolt 5, the second fixing bolt 7, and the third fixing bolt 8 mentioned in this application are only distinguished by their different positions and do not have any order of precedence.

[0065] In addition, it should be noted that the orientation or positional relationship indicated by "vertical" and other terms in this application is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the purpose of simplifying the description and making it easier to understand, and is not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0066] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. Any combination of all embodiments provided by this utility model is within the protection scope of this utility model and will not be elaborated upon here.

[0067] The above provides a detailed description of the turbine generator set and its main shaft axial thrust reduction device provided by this utility model. Specific examples have been used to illustrate the principle and implementation of this utility model. The descriptions of the embodiments above are only for the purpose of helping to understand the method and core idea of ​​this utility model. It should be noted that those skilled in the art can make several improvements and modifications to this utility model without departing from the principle of this utility model, and these improvements and modifications also fall within the protection scope of the claims of this utility model.

Claims

1. A spindle axial thrust reduction device, characterized in that, include: The bracket (1) is installed near the end of the turbine's main shaft; A magnetic conductor (2) is disposed at the end of the main shaft; An electromagnet (3) is disposed on the support (1), and the electromagnet (3) and the magnetic conductor (2) are aligned and distributed. Excitation winding (4), which is located inside the electromagnet (3); A control device electrically connected to the excitation winding (4) is used to control the current of the excitation winding (4) so ​​that the electromagnet (3) generates the required magnetic force, which is used to reduce the axial water thrust borne by the thrust bearing.

2. The spindle axial thrust reduction device according to claim 1, characterized in that, The magnetic conductor (2) is fixed to the end of the main shaft by the first fixing bolt (5).

3. The spindle axial thrust reduction device according to claim 1, characterized in that, It also includes a mounting flange (6) for fixing the electromagnet (3) to the bracket (1), the mounting flange (6) being fixed to the bracket (1) by a second fixing bolt (7).

4. The spindle axial thrust reduction device according to claim 3, characterized in that, The electromagnet (3) is fixed to the mounting flange (6) by the third fixing bolt (8).

5. The spindle axial thrust reduction device according to any one of claims 1 to 4, characterized in that, The excitation winding (4) is sealed inside the electromagnet (3) with insulating glue.

6. The spindle axial thrust reduction device according to claim 5, characterized in that, The electromagnet (3) and the excitation winding (4) are coaxially arranged.

7. The spindle axial thrust reduction device according to any one of claims 1 to 4, characterized in that, The bracket (1) includes a base plate (11) that is attached to the ground, a frame (12) that is vertically mounted on the base plate (11), and a reinforcing rib (13). The electromagnet (3) is vertically mounted on the frame (12), and the reinforcing rib (13) is located on opposite sides of the frame (12) and is vertically mounted on the base plate (11).

8. The spindle axial thrust reduction device according to claim 7, characterized in that, The base plate (11) is provided with at least four anchor bolts (14) along the circumference, and the anchor bolts (14) are used to fix the base plate (11) to the ground.

9. The spindle axial thrust reduction device according to any one of claims 1 to 4, characterized in that, It also includes a detection device for detecting the axial water thrust borne by the thrust bearing, the detection device being connected to the control device.

10. A water turbine unit, characterized in that, Includes the spindle axial thrust reduction device as described in any one of claims 1 to 9.

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