A gearbox thermal balance control system and method

Abstract

This invention belongs to the field of wind power equipment technology, specifically relating to a gearbox thermal balance control system, and more specifically to an intelligent auxiliary cooling system for high-speed shaft bearings in wind turbine gearboxes, as well as an intelligent thermal balance control method. The gearbox thermal balance control system of this invention is a device for auxiliary cooling control of high-speed shaft bearings in a gearbox based on an existing general-purpose gearbox. The system uses an oil extraction pipeline to precisely spray lubricating oil from the gearbox's oil distributor to the high-speed shaft bearing area requiring cooling. This artificially controls the distribution of lubricating oil from the distributor, which normally has a fixed oil path and flow rate, towards the high-speed shaft bearing area, increasing the amount of lubricating oil flowing into the bearing. By auxiliaryly spraying lubricating oil, auxiliary cooling and lubrication of the high-speed shaft bearing are achieved, ensuring the supply of lubricating oil during operation and guaranteeing the normal operation of the high-speed shaft bearing.

Description

Technical Field

[0001] This invention belongs to the field of wind power equipment technology, specifically relating to a gearbox thermal balance control system, and more specifically to an intelligent auxiliary cooling system for high-speed shaft bearings in wind turbine gearboxes, as well as an intelligent thermal balance control method. Background Technology

[0002] In recent years, with the rapid development of wind power generation, the installed capacity has increased year by year, and the daily maintenance of wind turbines has become an important factor affecting their working efficiency. The gearbox is the component of the wind turbine with the highest failure rate and the greatest maintenance difficulty. After a period of operation, due to the influence of system structure, operating environment and control method on the lifespan of each component, components with short lifespans, especially those with relative movement, will gradually develop problems after long-term operation.

[0003] Due to the unique structure of wind turbine gearboxes, especially the high-speed shaft which is typically positioned above the central horizontal plane, its bearings rely entirely on forced lubrication during operation, requiring a sufficient supply of lubricating oil. In existing gearbox high-speed shaft structures, an oil inlet is usually located above the bearing housing. Lubricating oil enters the lubrication chamber between the two bearings through radial oil injection holes opened on the bearing adjusting ring. When the oil level in the lubrication chamber reaches the height of the rollers, it flows over the rollers, thus lubricating the bearings. Under normal operating conditions, this lubrication method is sufficient for bearing lubrication, and the bearings do not generate high temperatures. However, under certain extreme conditions, such as high-temperature operation or overspeed operation, the heat generated by agitating the lubricating oil increases. Simultaneously, hot oil splashed from the high-speed rotation of the gears can also enter the bearing area from the side. This mixed oil lubrication hinders heat dissipation from the bearings, leading to high bearing temperatures. Furthermore, the wear of meshing gear teeth, the creeping and even sliding friction between bearing rolling elements and inner and outer rings, the outer ring of the bearing and the housing, and the wear of rotating parts will all gradually increase with the service life of the gearbox, and this process is irreversible. This leads to the failure of the gearbox's original thermal balance, causing continuous high-temperature alarms at temperature measurement points such as oil temperature and bearing temperature, forcing the fan to operate with limited power or even shut down, resulting in huge economic losses. Even worse, the increased temperature of rotating parts in the gearbox can even cause local overheating, resulting in fundamental changes in the material itself, a decrease in hardness and wear resistance, tooth surface scuffing, wear, tooth breakage, rapid bearing wear, shaft misalignment, and increased vibration. Therefore, gearbox temperature rise has become the root cause of most catastrophic failures.

[0004] Currently, the conventional maintenance methods for gearbox overheating in China include annual filter replacement, cleaning of the heat sink, replacement of accessories such as temperature control valves, replacement of high-power heat sinks, fans, or motors, or increasing ventilation to lower the engine compartment temperature, and even replacing high-speed shaft bearings. However, these methods only reduce the temperature by 1-3°C, resulting in minimal improvement. Moreover, since the wear of rotating parts is irreversible, simply replacing auxiliary equipment will cause the gearbox to return to an overheating state after a period of operation, and the problem will recur. Therefore, when the gearbox oil sump temperature is normal, but the bearing temperatures at both ends of the high-speed shaft are excessively high, replacing auxiliary equipment cannot fundamentally solve the problem and severely impacts operational efficiency. Summary of the Invention

[0005] Therefore, the technical problem to be solved by the present invention is to provide a gearbox thermal balance control system, which can assist in the intelligent cooling control of the high-speed shaft bearing of the wind turbine gearbox during operation, fundamentally solve the problem of gearbox bearing overheating, and ensure the efficient operation of the gearbox and the wind turbine.

[0006] The second technical problem to be solved by the present invention is to provide a method for regulating the thermal balance of a gearbox.

[0007] To solve the above-mentioned technical problems, the present invention provides a gearbox thermal balance control system, including an oil pump, and an oil pumping pipeline and an oil injection pipeline respectively connected to the oil pump.

[0008] The other end of the oil extraction pipeline is connected to the oil distributor of the gearbox, and lubricating oil is extracted from the oil distributor under the control of the oil pump; the other end of the oil injection pipeline extends into the high-speed shaft bearing area of ​​the gearbox, and the extracted lubricating oil is sprayed into the high-speed shaft bearing area under the control of the oil pump to achieve auxiliary cooling control of the high-speed shaft bearing.

[0009] Specifically, the oil injection pipe is provided with multiple sets of nozzles at the end position where it extends into the high-speed shaft bearing area, which can perform targeted oil injection on the high-speed shaft bearing.

[0010] The nozzle includes a first nozzle and a second nozzle that spray oil onto the bearings at both ends of the high-speed shaft bearing region, respectively.

[0011] Specifically, the nozzle of the fuel injection line extends into the high-speed shaft bearing area through the sight glass cover of the gearbox.

[0012] Specifically, a lubrication distribution bracket protruding from the surface of the gearbox is provided at the location of the viewing hole cover, and the nozzle extends through the lubrication distribution bracket into the interior of the high-speed shaft bearing area.

[0013] Specifically, a filter and / or cooler are provided between the oil pump and the oil injection pipeline to achieve secondary filtration and / or secondary cooling of the extracted lubricating oil.

[0014] Specifically, the oil pump is a variable flow pump controlled by a variable frequency speed control motor.

[0015] Specifically, the variable frequency speed control motor is controlled by a control system component, which automatically adjusts the oil extraction volume of the oil extraction pipeline and the oil injection volume of the oil injection pipeline by detecting the temperature change in the high-speed shaft bearing area.

[0016] The present invention also discloses an installation method for the gearbox thermal balance control system, including the steps of connecting the oil extraction pipeline and the oil injection pipeline to the oil pump respectively, the steps of drilling, connecting and fixing the other end of the oil extraction pipeline to the oil distributor of the gearbox, and the steps of drilling, connecting and fixing the other end of the oil injection pipeline to the high-speed shaft bearing area housing.

[0017] The present invention also discloses a method for gearbox thermal balance control based on the system, comprising the following steps:

[0018] (1) Install, connect and fix the system to the gearbox according to the method described above;

[0019] (2) Start the oil pump and extract lubricating oil from inside the oil distributor through the oil extraction pipeline;

[0020] (3) Under the action of the oil pump, the extracted lubricating oil is injected into the high-speed shaft bearing through the oil injection pipeline to achieve auxiliary cooling of the high-speed shaft bearing.

[0021] Specifically, the gearbox thermal balance control method further includes the step of monitoring the temperature of the high-speed shaft bearing, and the step of using the control system component to control the frequency of the variable frequency speed control motor to automatically adjust the oil extraction volume of the oil extraction pipeline and the oil injection volume of the oil injection pipeline.

[0022] The gearbox thermal balance control system of this invention is a device for auxiliary cooling control of the high-speed shaft bearings of a gearbox based on an existing general-purpose gearbox. The system uses an oil extraction pipeline to spray lubricating oil from the gearbox's oil distributor at specific points to the high-speed shaft bearing area that needs cooling. That is, the lubricating oil, which originally had a fixed oil path and flow distribution in the oil distributor, is artificially controlled to be directed more towards the high-speed shaft bearing area, increasing the amount of lubricating oil flowing into the high-speed shaft bearing. By auxiliaryly spraying lubricating oil, auxiliary cooling and lubrication of the high-speed shaft bearing are achieved, ensuring the supply of lubricating oil during the operation of the high-speed shaft bearing and guaranteeing its normal operation.

[0023] The gearbox thermal balance control system of this invention, through careful study of the overheating phenomenon during the operation of high-speed shaft bearings, utilizes different nozzle settings in the oil injection pipeline to achieve point-to-point oil injection at locations with high oil demand, precisely assisting in the cooling control of high-speed shaft bearings, while maximizing the normal operation of other oil circuits in the oil distributor.

[0024] The gearbox thermal balance control system of the present invention further utilizes the PLC component to control the frequency of the variable frequency speed control motor to automatically adjust the oil extraction volume of the oil extraction pipeline and the oil injection volume of the oil injection pipeline, and utilizes the temperature feedback of the temperature sensor to realize the automatic start of the system, as well as the "precise" oil injection cooling mode that can automatically adjust the flow rate, thereby realizing intelligent control of the thermal balance of the entire gearbox. Attached Figure Description

[0025] To make the content of this invention easier to understand, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings, wherein...

[0026] Figure 1 This is a schematic diagram of the structure of the system described in this invention connected to an existing gearbox;

[0027] Figure 2 This is a schematic diagram of the system described in this invention;

[0028] Figure 3 This is a schematic diagram showing the connection at the viewing hole cover position of the system described in this invention;

[0029] Figure 4 This is a schematic diagram of the control logic of the intelligent thermal balance control system for gearboxes described in this invention.

[0030] The reference numerals in the diagram are as follows: 1-Oil pump, 2-Oil extraction line, 3-Injection line, 4-Nozzle, 5-Filter, 6-Motor, 7-Cooler, 8-Temperature sensor, 9-Pressure sensor, 10-Differential pressure sensor, 11-Gearbox, 12-Oil distributor, 13-High-speed shaft bearing area, 14-Sight hole cover, 15-Lubrication distribution bracket, 16-Control system component Detailed Implementation

[0031] like Figure 1-2 The structure shown in this invention, the gearbox thermal balance control system, is a device for auxiliary cooling and control of the high-speed shaft bearing of a gearbox based on existing general-purpose gearboxes (especially wind power gearboxes), in order to achieve the control of gearbox thermal balance and thus solve the problem of overheating of the high-speed shaft bearing during gearbox operation.

[0032] like Figure 1-2 The structure shown in the invention, the gearbox thermal balance control system, includes an oil pump 1, and an oil extraction pipeline 2 and an oil injection pipeline 3 respectively connected to the oil pump 1; the oil pump 1 is controlled by a motor 6, thereby realizing the control of the oil extraction pipeline 2 and the oil injection pipeline 3.

[0033] like Figure 1-2 As shown in the structure, the oil extraction pipe 2, at its end away from the oil pump 1, is connected to the oil distributor 12 of the gearbox 11, thereby drawing lubricating oil from the oil distributor 12 under the control of the oil pump 1. Meanwhile, the oil spray pipe 3, at its end away from the oil pump 1, extends through the housing of the gearbox 11 into the high-speed shaft bearing area 13 of the gearbox 11. Under the control of the oil pump 1, the lubricating oil drawn by the oil extraction pipe 1 is sprayed into the high-speed shaft bearing position in the high-speed shaft bearing area 13, achieving auxiliary cooling control of the high-speed shaft bearing by auxiliary lubrication. Since the lubricating oil is drawn from the oil distributor 12, and has undergone filtration and cooling treatment during previous system operation, it can not only be directly sprayed into the high-speed shaft bearing operating area for lubrication, but also, being in a low-temperature cooled state, can be directly used for auxiliary cooling.

[0034] like Figure 1-3 As shown in the structure, in the system described in this invention, the oil injection pipe 3 needs to pass through the housing of the gearbox and extend into the high-speed shaft bearing area 13 for targeted oil injection. Considering the ease of installation of the entire system, the present invention preferably positions the oil injection pipe 3 at the location where it is drilled and fixed via the sight glass cover 14 of the gearbox 11. This location not only facilitates the installation of the oil injection pipe 3 but also facilitates subsequent observation and adjustment of the targeted oil injection effect.

[0035] Considering the ease of installation of the entire system based on the gearbox structure, the present invention preferably optimizes and improves the position of the viewing cover 14 during installation. For example... Figure 2-3 The structure shown allows for the design of a lubrication distribution bracket 15, which can be formed along the boundary of the sight cover 14, based on the dimensions of the sight cover area. During system installation, the original sight cover 14 of the gearbox 11 is first removed. The lubrication distribution bracket 15 is then fixed protruding from the housing surface along the circumferential position of the sight cover 14, thus forming a structure where the lubrication distribution bracket 15 protrudes longitudinally from the gearbox surface. Afterward, the sight cover 14 is connected and fixed to the lubrication distribution bracket 15 without affecting the function or observation effect of the sight cover. The fuel injection pipe 3 can be directly drilled, inserted, and fixed onto the lubrication distribution bracket 15, facilitating its installation and fixation without affecting the overall observation effect of the sight cover 14.

[0036] like Figure 1-3 The structure shown considers that during actual operation of the high-speed shaft, the bearings at both ends (i.e., the front and rear bearings) are the areas with the highest overheating and the most severe failures and damage. Therefore, the oil injection pipe 3 of this invention is equipped with multiple sets of nozzles 4 at the end of the oil injection pipe extending into the bearing area 13 of the high-speed shaft. This allows for targeted oil injection at these predetermined locations, achieving rapid cooling of the high-speed shaft bearings and minimizing oil extraction, effectively ensuring the lubricating oil supply to other oil circuits in the oil distributor 12. Specifically, the nozzles 4 include a first nozzle and a second nozzle that respectively spray oil onto the bearings at both ends of the high-speed shaft bearing area 13. This allows for concentrated targeted oil injection cooling at these two key locations (front and rear bearings), and reasonable distribution of lubricating oil to the front and rear bearings. The newly added oil injection pipes at the front and rear bearings of the high-speed shaft spray directly onto the bearing balls. The oil pipe path is reasonable, and the connection between the oil pipe structure and the gearbox structure is sealed with O-rings and flat sealant to ensure no lubricating oil leakage. The actual operation results have also proven that targeted oil injection at the two locations mentioned above can completely achieve the cooling operation of the entire high-speed shaft bearing, that is, adjust and solve the overheating problem of the gearbox high-speed shaft bearing with the least amount of oil.

[0037] like Figure 1-2 As shown in the structure, the gearbox thermal balance control system of the present invention can further be equipped with a filter 5 and / or a cooler 7 between the oil pump 1 and the oil injection pipeline 3 in order to better achieve cooling control of the high-speed shaft bearing. This achieves secondary filtration and / or secondary cooling of the extracted lubricating oil. The positions of the two are not particularly limited, and both can further purify and cool the extracted lubricating oil, effectively ensuring the stable operation of the system.

[0038] Furthermore, to achieve stable control of the entire system operation, a pressure sensor 9 and a differential pressure sensor 10 are further installed between the oil pump 1 and the oil injection pipeline 3 to facilitate monitoring of safety and temperature operation throughout the oil circuit. Considering the need for precise control of the entire auxiliary cooling process, a temperature sensor 8 can also be installed at the location of the high-speed shaft bearing area 13 to facilitate temperature monitoring and control throughout the oil injection and operation processes.

[0039] like Figure 1-2 As shown in the structure, the oil pump 1 of the present invention is a power pump controlled by the motor 6. The motor 6 can be a fixed-speed motor used in traditional gearboxes, that is, the frequency and other parameters of the motor can be selected according to empirical values, so that the entire oil circuit can operate normally and ensure sufficient and stable oil injection.

[0040] In order to better and more accurately control and operate the entire oil injection cooling process, the gearbox thermal balance control system of the present invention preferably uses a variable frequency speed control motor 6, thereby controlling the oil pump 1 to be a controllable variable flow pump. The variable frequency speed control motor 6 can be controlled by a pre-set PLC program in the control system. The temperature sensor 8 monitors the temperature change of the high-speed shaft bearing area 13, and the PLC program in the control system automatically adjusts the oil extraction volume of the oil extraction pipeline 2 and the oil injection volume of the oil injection pipeline 3, realizing "on-demand" start-up and "precise" oil injection cooling of the high-speed shaft bearing, thereby achieving automated control, effectively saving the workload of manual inspection, and minimizing potential damage to the gearbox high-speed shaft bearing during operation.

[0041] The gearbox thermal balance control system of the present invention can be installed as an improvement on an existing gearbox, or it can be installed as a raw material during gearbox assembly. The entire installation process only requires connecting the oil extraction line 2 and the oil injection line 3 to the oil pump 1 in a conventional manner (optionally, a filter, cooler, pressure sensor, etc. can be installed). Then, the other end of the oil extraction line 2 is drilled, connected, and fixed to the oil distributor of the gearbox using conventional installation methods. Finally, the other end of the oil injection line 3 is drilled, connected, and fixed to the housing of the high-speed shaft bearing area 13 (preferably installed at the location of the sight glass cover).

[0042] When the gearbox thermal balance control system of the present invention is running, it can be manually activated when the high-speed shaft bearing experiences overheating. The oil pump 1 is started, and lubricating oil is drawn from the oil distributor through the oil extraction pipeline 2. Under the action of the oil pump 1, the drawn lubricating oil is sprayed onto the high-speed shaft bearing at a fixed point through the oil injection pipeline 3. This is equivalent to using external lubricating oil to assist in cooling the high-speed shaft bearing and solve the problem of overheating damage to the high-speed shaft bearing.

[0043] As a preferred embodiment, the gearbox thermal balance control system of the present invention can, during operation, conduct statistical experiments in advance to test the correlation between the actual temperature of the high-speed shaft bearing and the cooling range of the oil injection quantity. Then, the control system components are used to control the frequency of the variable frequency speed control motor 6 to automatically adjust the oil extraction quantity of the oil extraction pipeline 2 and the oil injection quantity of the oil injection pipeline 3. The temperature feedback of the temperature sensor is used to realize the automatic start of the system and the "precise" oil injection cooling mode that can automatically adjust the flow rate, thereby realizing intelligent control of the thermal balance of the entire gearbox.

[0044] Specifically, the control logic of the gearbox thermal balance intelligent regulation system described in this invention is as follows: Figure 4 As shown, the specific functions are described below:

[0045] (1) System startup: The system is powered on;

[0046] (2) Manual maintenance: When the system enters manual maintenance mode, the user can manually start the motor and manually change the motor speed;

[0047] (3) Automatic start-up: The system enters automatic operation mode;

[0048] (4) System self-test: The system automatically detects the status of PLC, inverter, external environment, etc. If there is no fault, it proceeds to the next step; if there is a fault, the system exits the automatic state and alarms the on-duty personnel.

[0049] (5) After the system self-test is completed, it will determine whether the condition "actual temperature is higher than startup temperature" is met. If the condition is met, proceed to the next step; otherwise, return.

[0050] (6) Motor start-up, that is, the motor is in operation and can receive commands at any time to adjust the speed;

[0051] (7) Real-time temperature detection: The system detects the actual temperature in real time through a temperature sensor;

[0052] (8) Real-time oil pressure detection: The system detects the actual temperature in real time through a pressure sensor;

[0053] (9) Adjustment of actual motor speed: The system adjusts the actual motor speed by executing the core algorithm based on the collected actual temperature and oil pressure values ​​to achieve the effect of gearbox oil temperature thermal balance.

[0054] (10) During automatic operation, if the condition of "actual temperature is lower than starting temperature" is met, the motor is stopped and the process returns to the step of "actual temperature is higher than starting temperature"; if the condition is not met, the process continues to adjust the actual motor speed by detecting temperature and oil pressure.

[0055] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A gearbox thermal balance control system, characterized in that, It includes an oil pump (1), and an oil pumping line (2) and an oil injection line (3) respectively connected to the oil pump (1). The other end of the oil extraction pipeline (2) is connected to the oil distributor (12) of the gearbox (11), and lubricating oil is extracted from the oil distributor (12) under the control of the oil pump (1); the other end of the oil injection pipeline (3) extends into the high-speed shaft bearing area (13) of the gearbox (11), and the extracted lubricating oil is sprayed into the high-speed shaft bearing area (13) under the control of the oil pump (1) to achieve auxiliary cooling control of the high-speed shaft bearing; The oil injection pipe (3) is provided with multiple sets of nozzles (4) at the end position of the high-speed shaft bearing area (13) that can perform fixed-point oil injection on the high-speed shaft bearing. The nozzle (4) includes a first nozzle and a second nozzle that spray oil onto the bearings at both ends of the high-speed shaft bearing region (13), respectively. The nozzle (4) of the fuel injection line (3) extends into the high-speed shaft bearing area (13) through the sight cover (14) of the gearbox. A lubrication distribution bracket (15) is formed at the boundary position of the viewing hole cover (14). A filter (5) and / or a cooler (7) are provided between the oil pump (1) and the oil injection line (3). A pressure sensor (9) and a differential pressure sensor (10) are provided between the oil pump (1) and the oil injection pipeline (3). The oil pump (1) is a variable flow pump controlled by a variable frequency speed control motor (6); The variable frequency speed control motor (6) is controlled by a control system component including a frequency converter and a PLC component. By detecting the temperature change of the high-speed shaft bearing area (13), the oil pumping volume of the oil pumping pipeline (2) and the oil injection volume of the oil injection pipeline (3) are automatically adjusted.

2. A method for installing the gearbox thermal balance control system as described in claim 1, characterized in that, The steps include connecting the oil extraction line (2) and the oil injection line (3) to the oil pump (1), drilling, connecting and fixing the other end of the oil extraction line (2) to the oil distributor of the gearbox, and drilling, connecting and fixing the other end of the oil injection line (3) to the housing of the high-speed shaft bearing area (13).

3. A method for gearbox thermal balance control based on the gearbox thermal balance control system of claim 1, characterized in that, Includes the following steps: (1) The gearbox thermal balance control system is installed, connected and fixed to the gearbox according to the method described in claim 2; (2) Start the oil pump (1) and extract lubricating oil from inside the oil distributor through the oil extraction pipeline (2); (3) Under the action of the oil pump (1), the extracted lubricating oil is injected into the high-speed shaft bearing through the oil injection pipeline (3) to achieve auxiliary cooling of the high-speed shaft bearing.

4. The method for gearbox thermal balance control according to claim 3, characterized in that, It also includes the step of monitoring the temperature of the high-speed shaft bearing, and the step of controlling the frequency of the variable frequency speed control motor (6) using the control system component to automatically adjust the oil pumping volume of the oil pumping line (2) and the oil injection volume of the oil injection line (3).

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