Generator bearing sealing structure capable of dynamically adjusting grease discharge and control method

Abstract

The invention discloses a generator bearing sealing structure capable of dynamically adjusting grease discharge, which comprises a staged sealing cavity, a self-adaptive grease discharge channel and a multi-stage sealing assembly, reduces the mixing rate of new and old grease through double-cavity physical isolation and centrifugal impurity separation, and dynamically adjusts the grease discharge amount by adopting a spiral diversion trench and a temperature control throttle valve. And through a'pressure-temperature-flow 'triple monitoring system and viscosity-temperature coupling control, it is ensured that grease can be normally discharged in a low-temperature environment, the stability and controllability of waste grease discharging are ensured, and an efficient impurity separation mechanism is formed through organic combination of a spiral flow guide groove and a magnetic adsorption ring. Solid impurities gather towards the wall face of the auxiliary sealing cavity under the action of centrifugal force, the magnetic adsorption ring can capture metal abrasion particles in waste grease, abrasion of the impurities to the bearing is effectively reduced, the service life of the bearing is prolonged, and the operation efficiency of a lubricating system is improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of wind power generation equipment, and particularly relates to a generator bearing sealing structure capable of dynamically adjusting grease discharge and a control method. BACKGROUND

[0002] The conventional bearing sealing structure of the lubricating system cannot distinguish between new grease and waste grease, resulting in waste grease residue or new grease waste. The existing sealing structures such as labyrinth sealing and lip sealing can separate new and old greases, but the waste grease is prone to accumulation in the sealing cavity or rapid discharge due to high viscosity, especially after intermittent blockage caused by poor grease flowability, which suddenly causes leakage. There is a defect that the difference in grease flowability is not considered, and the waste grease cannot be discharged controllably.

[0003] Chinese patent document CN222192047U discloses a structure using a centrifugal oil pan and an inner oil seal to form a multiple labyrinth sealing structure, to realize sufficient lubrication through an oil injection hole and an oil channel of an inner and outer bearing chamber, and to discharge waste oil through a waste oil collection channel. However, due to the viscosity of the grease, there is a problem of response lag during operation, which cannot timely adjust the discharge amount according to the actual state of the waste grease, resulting in unstable discharge of the waste grease. SUMMARY

[0004] To solve the above problems, the application discloses a generator bearing sealing structure capable of dynamically adjusting grease discharge and a control method, which can optimize the discharge rate of high-viscosity waste oil, prevent poor oil discharge or excessive oil discharge, and improve the operation stability and reliability of the wind turbine bearing lubricating system.

[0005] To achieve the above purpose, the technical scheme of the application is as follows: A generator bearing sealing structure capable of dynamically adjusting grease discharge, comprising a sealing ring, wherein a hierarchical sealing cavity, a self-adaptive grease discharge channel and a multi-stage sealing assembly are arranged in the sealing ring, The hierarchical sealing cavity comprises a main sealing cavity for containing new grease, a buffer transition zone and a secondary sealing cavity for collecting waste grease, the main sealing cavity and the buffer transition zone are arranged on both sides of the bearing respectively, and the secondary sealing cavity is arranged outside the buffer transition zone; The self-adaptive grease discharge channel comprises a spiral flow guide groove arranged on the inner wall of the buffer transition zone and a temperature-controlled throttling valve integrated with a PTC heating element, the spiral flow guide groove is a variable-pitch thread structure, the outlet of the spiral flow guide groove is communicated with the secondary sealing cavity, the temperature-controlled throttling valve is arranged at the outlet of the secondary sealing cavity, a magnetic adsorption ring is arranged outside the spiral flow guide groove, a pressure sensor and a temperature sensor are arranged in the secondary sealing cavity, and the pressure sensor and the temperature sensor are connected with the temperature-controlled throttling valve, The multi-stage sealing assembly is provided with an external first non-contact labyrinth seal and an internal composite lip seal on the main sealing cavity side, and a stepped second non-contact labyrinth seal on the secondary sealing cavity side.

[0006] As a supplement to the present invention, a hemispherical check baffle is provided at the outlet of the spiral guide groove.

[0007] As a supplement to the present invention, the lip angle of the composite lip seal is 60±5°, and the sealing material is fluororubber+graphite coating.

[0008] As a supplement to the present invention, the pitch range of the spiral guide groove is 5-20 mm, and the axial decreasing rate is 10%-20% / turn.

[0009] As a supplement to the present invention, a temperature-controlled throttle valve controls the waste grease to be discharged at a flow rate of 0.5-2 mL / min.

[0010] As a supplement to the present invention, a composite lip seal is also provided on the secondary sealing cavity side.

[0011] A grease discharge control method for a generator bearing seal structure capable of dynamically adjusting grease discharge comprises the following steps: During the operation of the wind turbine, the solid impurities and waste oil liquid in the waste grease are graded and separated by centrifugal force, so that the solid impurities gather on the wall of the secondary sealing cavity, and the magnetic adsorption ring captures the metal wear particles in the solid impurities, while the waste oil liquid flows along the guide groove to the temperature-controlled throttle valve. The pressure and temperature of the waste oil in the secondary sealing chamber are monitored in real time by a pressure sensor and a temperature sensor arranged in the secondary sealing chamber; When the temperature is lower than 40°C and the pressure is greater than the preset value, increase the opening of the temperature-controlled throttle valve; The discharge flow of waste oil is monitored by the flow rate monitoring point set in the grease discharge channel, and an alarm is triggered when the flow rate exceeds the tolerance; According to the pressure and temperature monitoring data, the opening of the temperature-controlled throttle valve is adjusted through the PID control algorithm to achieve the discharge of waste oil at a constant flow rate.

[0012] The beneficial effects of the present invention are: (1) The invention's unique "pressure-temperature-flow" triple monitoring system and viscosity-temperature coupled control significantly reduce the failure rate compared to traditional single-sensor control. The low-temperature start-up mode automatically increases the valve opening, maintaining optimal grease fluidity through heating, ensuring grease discharge stability and avoiding the inability of traditional structures to discharge grease in low-temperature environments.

[0013] (2) The unique "spiral guide groove + temperature control throttle valve" is used to dynamically adjust the grease discharge, which can maintain a constant flow rate through real-time feedback control. Compared with the traditional natural discharge relying on gravity or pressure, it reduces the fluctuation rate of grease discharge flow, improves the situation where waste grease is easily blocked, and ensures the controllability of waste grease discharge.

[0014] (3) The three-level collaborative seal sets up a labyrinth seal to block new grease, the buffer transition zone reduces pressure, and the composite seal adapts to the characteristics of waste grease. Compared with the traditional single seal, the service life is improved. Through dual-cavity physical isolation + centrifugal impurity separation, the mixing rate of new and old grease is reduced.

[0015] (4) Impurity separation mechanism: The organic combination of the spiral guide groove and the magnetic adsorption ring forms an efficient impurity separation mechanism. Under the action of centrifugal force, solid impurities gather on the wall of the secondary seal cavity, while the magnetic adsorption ring can capture metal wear particles in the waste grease, effectively reducing the wear of impurities on the bearing, thereby improving the service life of the bearing and the operating efficiency of the lubrication system. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a structural schematic diagram of the present invention.

[0017] Figure 2 This is a schematic diagram of the sealing element on the main sealing cavity side of the present invention.

[0018] Figure 3 This is a block diagram of the working principle of the temperature-controlled throttle valve described in the present invention.

[0019] List of Figure Symbols: 1. Sealing ring, 2. Grease discharge channel, 3. Multi-stage sealing assembly, 4. Main sealing chamber, 5. Buffer transition zone, 6. Secondary sealing chamber, 7. Spiral guide groove, 8. Temperature-controlled throttle valve, 9. Magnetic adsorption ring, 10. First non-contact labyrinth seal, 11. Composite lip seal, 12. Stepped second non-contact labyrinth seal, 13. Hemispherical check baffle, 14. Bearing. DETAILED DESCRIPTION

[0020] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. It should be understood that the following specific embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention.

[0021] like Figure 1 As shown, the generator bearing sealing structure capable of dynamically adjusting grease removal according to the present invention comprises a sealing ring 1, wherein the sealing ring 1 is provided with a hierarchical sealing cavity, an adaptive grease removal channel 2 and a multi-stage sealing component 3. The hierarchical sealing cavity includes a main sealing cavity 4 for accommodating new grease, a buffer transition zone 5, and a secondary sealing cavity 6 for collecting waste grease. The main sealing cavity 4 and the buffer transition zone 5 are respectively arranged on both sides of the bearing 14, and the secondary sealing cavity 6 is arranged outside the buffer transition zone 5. The adaptive fat discharge channel 2 includes a spiral guide groove 7 arranged on the inner wall of the buffer transition zone and a temperature-controlled throttle valve 8 with an integrated PTC heating element. The spiral guide groove 7 is a variable pitch thread structure. The outlet of the spiral guide groove 7 is connected to the secondary sealing chamber 6. The temperature-controlled throttle valve 8 is arranged at the outlet of the secondary sealing chamber. A magnetic adsorption ring 9 is provided on the outside of the spiral guide groove 7. A pressure sensor and a temperature sensor are provided in the secondary sealing chamber 6. The pressure sensor and the temperature sensor are connected to the temperature-controlled throttle valve 8. The multi-stage sealing assembly 3 is provided with an external first non-contact labyrinth seal 10 and an internal composite lip seal 11 on the primary sealing cavity 4 side, and a stepped second non-contact labyrinth seal 12 on the secondary sealing cavity 6 side.

[0022] The generator bearing seal structure described in this invention, which enables dynamically adjustable grease removal, begins with an interference fit between the primary seal chamber and the bearing seat during assembly. The interference fit is controlled within a range of 0.02-0.05mm, ensuring a tight connection between the primary seal chamber and the bearing seat and preventing leakage of new grease. An integrated temperature-pressure sensor is installed at the bottom of the secondary seal chamber, with a sampling period of ≤100ms, enabling rapid and accurate monitoring of the waste grease temperature and pressure parameters within the secondary seal chamber.

[0023] Control Logic: When temperature sensor T1 detects a waste grease temperature T1 below 40°C and pressure sensor P1 detects a pressure P1 above 0.2 MPa, the control system increases the opening of the temperature-controlled throttle valve by 20% to facilitate the discharge of high-viscosity waste grease. Flow rate monitoring points are set within the grease discharge channel to monitor the waste grease discharge flow in real time. When the monitored flow rate exceeds the set normal range, an alarm is triggered, alerting maintenance personnel to conduct inspection and take corrective measures.

[0024] Furthermore, the combination of the spiral guide groove 7 and the magnetic adsorption ring 9 forms a highly efficient impurity separation mechanism. As the motor rotates, centrifugal force forces waste oil out of the grease drainage channel 2 at a controlled rate of 0.5-2 mL / min. Solid impurities accumulate on the walls of the secondary seal chamber, while the magnetic adsorption ring captures metallic wear particles in the waste oil, effectively reducing impurity wear on the bearings, thereby increasing bearing life and the efficiency of the lubrication system.

[0025] The pitch range of the spiral guide groove of the present invention is 5-20mm, and the axial decreasing rate is 10%-20% / turn. Its structure can throw out waste grease. A hemispherical check baffle 13 is provided at the outlet of the spiral guide groove 7 to prevent air inhalation during shutdown and cause the grease to dry up.

[0026] The composite lip seal 11 of the present invention has a lip angle of 60±5° and is made of fluororubber and graphite coating. Installed in the primary sealing chamber 4, it enhances sealing effectiveness. A composite lip seal is also installed in the secondary sealing chamber 6. The sealing material is a combination of fluororubber and graphite coating. Fluororubber exhibits excellent oil and temperature resistance, while the graphite coating effectively reduces grease adhesion to the sealing lip, further enhancing sealing effectiveness and waste grease removal.

[0027] The bearing sealing structure suitable for a wind power generation lubrication system and the waste grease discharge control method matched therewith described in the present invention not only have a good sealing effect, but also can optimize the discharge rate of high-viscosity waste grease, prevent poor grease discharge or excessive grease discharge, and improve the operating stability and reliability of the wind turbine bearing lubrication system.

[0028] It should be noted that the above content merely illustrates the technical idea of ​​the present invention and cannot be used to limit the scope of protection of the present invention. For ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications all fall within the scope of protection of the claims of the present invention.

Claims

1. A generator bearing sealing structure capable of dynamically adjusting grease removal, characterized by: It includes a sealing ring, which is provided with a hierarchical sealing cavity, an adaptive grease discharge channel and a multi-stage sealing component. The hierarchical sealing cavity includes a main sealing cavity for accommodating new grease, a buffer transition zone, and a secondary sealing cavity for collecting waste grease. The main sealing cavity and the buffer transition zone are respectively arranged on both sides of the bearing, and the secondary sealing cavity is arranged outside the buffer transition zone. The adaptive fat discharge channel includes a spiral guide groove arranged on the inner wall of the buffer transition zone and a temperature-controlled throttle valve with an integrated PTC heating element. The spiral guide groove is a variable pitch thread structure. The outlet of the spiral guide groove is connected to the secondary sealing cavity. The temperature-controlled throttle valve is arranged at the outlet of the secondary sealing cavity. A magnetic adsorption ring is provided on the outer side of the spiral guide groove. A pressure sensor and a temperature sensor are provided in the secondary sealing cavity. The pressure sensor and the temperature sensor are connected to the temperature-controlled throttle valve. The multi-stage sealing assembly is provided with an external first non-contact labyrinth seal and an internal composite lip seal on the main sealing cavity side, and a stepped second non-contact labyrinth seal on the secondary sealing cavity side.

2. The generator bearing sealing structure capable of dynamically adjusting grease removal according to claim 1, characterized in that: A hemispherical check baffle is provided at the outlet of the spiral guide groove.

3. The generator bearing sealing structure capable of dynamically adjusting grease removal according to claim 1, characterized in that: The lip angle of the composite lip seal is 60±5°, and the sealing material is fluororubber+graphite coating.

4. The generator bearing sealing structure capable of dynamically adjusting grease removal according to claim 1, characterized in that: The pitch range of the spiral guide groove is 5-20 mm, and the axial decreasing rate is 10%-20% / turn.

5. The generator bearing sealing structure capable of dynamically adjusting grease removal according to claim 1, characterized in that: The temperature-controlled throttle valve controls the discharge of waste grease at a flow rate of 0.5-2 mL / min.

6. The generator bearing sealing structure capable of dynamically adjusting grease removal according to claim 1, characterized in that: A composite lip seal is also provided on the secondary sealing cavity side.

7. A grease removal control method for a generator bearing seal structure capable of dynamically adjusting grease removal according to any one of claims 1 to 6, characterized in that: The following steps are involved: During the operation of the wind turbine, the solid impurities and waste oil liquid in the waste grease are graded and separated by centrifugal force, so that the solid impurities gather on the wall of the secondary sealing cavity, and the magnetic adsorption ring captures the metal wear particles in the solid impurities, while the waste oil liquid flows along the guide groove to the temperature-controlled throttle valve. The pressure and temperature of the waste oil in the secondary sealing chamber are monitored in real time by a pressure sensor and a temperature sensor arranged in the secondary sealing chamber; When the temperature is lower than 40°C and the pressure is greater than the preset value, increase the opening of the temperature-controlled throttle valve; The discharge flow of waste oil is monitored by the flow rate monitoring point set in the grease discharge channel, and an alarm is triggered when the flow rate exceeds the tolerance; According to the pressure and temperature monitoring data, the opening of the temperature-controlled throttle valve is adjusted through the PID control algorithm to achieve the discharge of waste oil at a constant flow rate.

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