A wind turbine variable pitch bearing oil sample collection device

Abstract

The application discloses a kind of wind power generator variable pitch bearing oil sample collection device and method, it is related to wind power operation and maintenance technical field.The device includes hollow probe rod, sealed sampling head, negative pressure liposuction component, sealed fat storage component and positioning auxiliary tool.Sealed sampling head includes center tube, sliding sleeve and deformable conical umbrella head, and conical petal is attached to the outer wall of center tube front end in closed state and covers and isolates sampling port.Negative pressure liposuction component is started, and negative pressure acts on conical petal to make its front end turn over outward and form initial gap, and reciprocating variable pitch of variable pitch system makes flowing working fat extrude into conical petal inside and push it away, form umbrella-shaped cover body towards front, and working fat is gathered to sampling port to complete sampling.The application is closed by conical petal Isolation and self-triggered opening flow guide, effectively avoids the pollution of non-representative fat, and improves sampling representativeness.

Description

Technical Field

[0001] This invention relates to a wind turbine pitch bearing oil sample collection device, belonging to the technical field of pitch bearing oil sample collection. Background Technology

[0002] Pitch bearings are one of the core components of wind turbines, and their health is crucial to turbine operation. Grease composition testing is a key method for assessing bearing health. Currently, wind farms face issues such as difficulty in obtaining grease from inside the bearings or sample sizes that are less than the minimum weight required for grease composition testing. This leads to delays in grease composition inspections and untimely assessments of bearing health.

[0003] Chinese patent CN220650177U discloses a bearing grease sampling device, including a housing, a gripping part, a negative pressure generating part, and a grease extraction tube. The housing has an installation cavity. The negative pressure generating part is used to transport the air in the installation cavity to the air outlet to be discharged outside the installation cavity. One end of the grease extraction tube is connected to the installation cavity, and the other end is used to extract grease from the bearing. The negative pressure generated by the negative pressure generating part creates negative pressure in the installation cavity, so that the grease extraction tube can be used to extract grease. However, this device relies solely on the grease extraction tube to passively extract grease. When faced with problems such as hardened grease obstructing the insertion in the oil drain hole channel of the pitch bearing, non-representative grease contaminating the sampling port, and the uncontrollable flow direction of the working grease leading to poor sampling representativeness, it is difficult to meet the need for high-representative oil sample collection of pitch bearings. Summary of the Invention

[0004] To address the aforementioned problems in the existing technology, this invention provides a wind turbine pitch bearing oil sampling device that can effectively avoid contamination by non-representative grease and improve the representativeness of the samples.

[0005] The technical solution of the present invention is as follows: A wind turbine pitch bearing oil sampling device includes a hollow probe, a sealed sampling head, a negative pressure grease suction assembly, a sealed grease storage assembly, and a positioning auxiliary fixture. The hollow probe has a segmented telescopic structure. The negative pressure grease suction assembly is connected to the rear end of the hollow probe. The positioning auxiliary fixture guides the sealed sampling head into the drain screw hole at a predetermined angle and depth. The sealed sampling head includes a central tube, a sliding sleeve, and a deformable conical umbrella head. The rear end of the central tube is fixedly connected to the front end of the hollow probe, and the open end face of the front end of the central tube forms the sampling port. The sliding sleeve is axially slidably fitted onto the probe. The front end face of the sliding sleeve is open on the outside of the central tube; the deformable conical umbrella head includes several conical petals, the rear end of each conical petal is hinged to the front end of the sliding sleeve by a torsion spring, and each conical petal has a tendency to close inward under the action of the torsion spring; an isolation elastic membrane is provided between each conical petal; in the closed state, the inner wall surface of each conical petal is against the outer wall of the front end of the central tube, completely covering the sampling port of the central tube; the internal cavity of the central tube is a sampling channel, one end of the sampling channel is a sampling port, and the other end is connected to the inner cavity of the hollow probe, and a one-way valve is provided at the sampling port.

[0006] The positioning auxiliary tooling includes a threaded limiting sleeve and an angle alignment block. The inner wall of the threaded limiting sleeve has a central through hole that penetrates the threaded limiting sleeve. The outer wall of the threaded limiting sleeve has an external thread that mates with the internal thread of the drain screw hole. The rear end face of the threaded limiting sleeve forms an axial limiting surface, which abuts against the stepped surface on the hollow probe to limit the depth to which the sealing sampling head extends into the drain screw hole. The angle alignment block is rotatably mounted on the outer periphery of the threaded limiting sleeve via a connecting bearing. The angle alignment block has a positioning key that matches the shape of the angle positioning groove at the opening of the drain screw hole.

[0007] The data acquisition device also includes a pitch coordination control module that is communicatively connected to the pitch control system of the wind turbine generator set. The pitch coordination control module is used to control the pitch system to perform reciprocating pitch during the sampling process to promote the flow of working grease on the raceway working surface. The pitch coordination control module is also electrically connected to the negative pressure liposuction component to trigger the start of the negative pressure liposuction component during sampling.

[0008] The central tube and the sliding sleeve are provided with a limiting structure, which includes a first limiting step on the outer wall of the central tube and a second limiting step on the inner wall of the sliding sleeve.

[0009] The sealed grease storage assembly includes a sampling bottle, the front end of which is detachably connected to the rear end of the hollow probe; the negative pressure grease aspiration assembly includes a negative pressure pump and a negative pressure tank, the negative pressure pump is connected to the negative pressure tank, and the negative pressure tank is connected to the rear end of the sampling bottle.

[0010] The central tube has a filter screen at the sampling port.

[0011] A method for collecting oil samples from the pitch bearing of a wind turbine includes the following steps: S1: Screw the threaded limit sleeve of the positioning auxiliary tooling into the oil drain hole of the pitch bearing, and make the positioning key on the angle alignment block embed into the angle positioning groove at the opening of the oil drain hole to lock the circumferential angle of the sealing sampling head. S2: Insert the hollow probe through the central through hole of the threaded limiting sleeve and push it forward until the stepped surface on the hollow probe abuts against the rear end face of the threaded limiting sleeve, so that the sealed sampling head reaches the predetermined depth. S3: The pitch control module controls the pitch system to perform reciprocating pitch, and at the same time, new grease is added through the grease inlet of the pitch bearing, so that the new grease displaces the working grease on the raceway working surface towards the sampling port; the working grease on the raceway working surface flows under the combined action of the pitch driving force and the grease displacement pressure, and the flowing working grease generates a backward axial thrust on the sliding sleeve and the deformable conical umbrella head, pushing the sliding sleeve to overcome the return spring force and slide backward relative to the central tube; when the sliding sleeve slides backward, it drives the rear end of each conical lobe to move backward, and the front end of each conical lobe is forced to flip outward by the limit of the front end outer wall of the central tube, forming an initial gap between the conical lobe and the front end of the central tube; S4: The pitch control module triggers the negative pressure liposuction component to start, generating negative pressure in the sampling channel and forming a fat flow field at the sampling port; the pitch control module controls the pitch system to continue reciprocating pitch and continuously injecting new fat. The flowing working fat is continuously squeezed into the interior of the cone-shaped flap through the initial gap, further overcoming the torsional spring force to push each cone-shaped flap outward, so that the deformable cone-shaped umbrella head switches from the closed state to the open state, forming a forward-facing umbrella-shaped cover; S5. The open, deformable conical umbrella head gathers the working grease from the pitch displacement to the sampling port, and under negative pressure, it enters the sealed grease storage component to complete the sampling. S6. The negative pressure liposuction component stops, the negative pressure in the sampling channel disappears, and each cone-shaped flap closes inward again under the action of the torsion spring, restoring the closed state and exiting the sealed sampling head.

[0012] In steps S3 and S4, the pitch control module's control of the pitch system satisfies the following timing sequence: T1 Pre-pitch Stage: The pitch coordination control module controls the pitch system to perform reciprocating pitch with an amplitude of ±3° to ±10° and a frequency of 0.1Hz to 0.5Hz for 10 to 60 seconds, causing the working grease on the raceway working surface to flow in a direction under the action of shear force. At this time, the negative pressure grease suction component has not yet been activated, nor has any new grease been added. T2 Grease Displacement Stage: Based on the T1 stage, new grease is added through the grease inlet of the pitch bearing. The injection pressure of the new grease is 2MPa to 8MPa, which displaces the working grease on the raceway working surface towards the sampling port. The flowing working grease generates a backward axial thrust on the sliding sleeve and the deformable conical umbrella head, pushing the sliding sleeve to slide backward against the force of the return spring, causing the rear end of the conical flap to move backward. The front end of the conical flap is limited by the outer wall of the front end of the central tube and flips outward to form an initial gap. At this time, the negative pressure grease suction assembly has not yet been activated. T3 Joint Sampling Stage: Based on the T1 and T2 stages, the pitch control module triggers the negative pressure liposuction component to start, generating negative pressure in the sampling channel; the pitch system continues to reciprocate and continuously inject new liposuction, and the flowing working liposuction is continuously squeezed into the interior of the conical flap through the initial gap formed in the T2 stage, further overcoming the torsional spring force to push each conical flap outward, so that the deformable conical umbrella head switches from the closed state to the open state; T4 Pressure Holding and Sampling Stage: The pitch control module maintains the continuous operation of the pitch system and the grease displacement, while the negative pressure grease suction component continues to work. The open umbrella-shaped cover gathers the working grease from the pitch displacement to the sampling port, and enters the sealed grease storage component under negative pressure, continuously sampling for 30 to 120 seconds. T5 Termination Stage: The pitch control module first controls the negative pressure liposuction component to stop, then stops fat displacement, and finally controls the pitch system to stop pitching.

[0013] The present invention has the following beneficial effects: This invention achieves isolation and protection of the sampling port during insertion by having each conical petal of the deformable conical umbrella head abut against the outer wall of the front end of the central tube in the closed state and completely covering the sampling port. This invention controls the pitch system to perform reciprocating pitch changes through a pitch control module, while simultaneously adding new grease to displace the working grease on the raceway surface. This causes the flowing working grease to generate a rearward axial thrust on the sliding sleeve and the deformable conical umbrella head, pushing the sliding sleeve to slide backward against the force of the return spring. The backward movement of the sliding sleeve causes the rear end of the conical flap to move backward, and the front end of the conical flap is limited by the outer wall of the front end of the central tube and flips outward to form an initial gap. Then, the negative pressure grease suction component is triggered to start, allowing the flowing working grease to be continuously squeezed into the interior of the conical flap through the initial gap and completely pushed open, realizing the self-triggered switching of the deformable conical umbrella head from a closed state to an open state.

[0014] This invention forms an umbrella-shaped cover with a large opening facing the working surface of the raceway and a small opening connecting with the sampling port after the deformable conical umbrella head is opened. This achieves the collection and guidance of the working grease driven by the pitch, thereby improving the representativeness and efficiency of the sampling.

[0015] This invention controls the pitch system to perform reciprocating pitch changes through a pitch control module, while simultaneously controlling the addition of new grease to replace the working grease on the raceway working surface. This achieves the directional pushing of the actual working grease that has participated in shearing and load-bearing on the raceway working surface of the pitch bearing towards the sampling port, thus enabling the collected samples to accurately reflect the bearing wear state and the degree of grease deterioration. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the closure of the deformable conical umbrella head of the present invention; Figure 2 This is a schematic diagram of the deformable conical umbrella head of the present invention when it is open; Figure 3 This is a schematic diagram of the negative pressure liposuction assembly and the sealed liposuction storage assembly of the present invention; Figure 4 This is a schematic diagram of the positioning auxiliary tooling of the present invention.

[0017] The reference numerals in the figure are as follows: 1. Hollow probe; 2. Central tube; 3. Sliding sleeve; 4. Deformable conical umbrella head; 5. Threaded limiting sleeve; 6. Angle alignment block; 7. Connecting bearing; 8. Sampling bottle; 9. Negative pressure pump; 11. Stepped surface; 21. Sampling port; 41. Conical flap; 42. Isolation elastic membrane; 51. Axial limiting surface; 91. Negative pressure tank. Detailed Implementation

[0018] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0019] Please see Figures 1 to 4 The invention provides a technical solution: The wind turbine pitch bearing oil sampling device of this embodiment includes a hollow probe 1, a sealed sampling head, a negative pressure grease suction assembly, a sealed grease storage assembly, and a positioning auxiliary fixture. The hollow probe 1 is a segmented telescopic structure, and its length can be adjusted according to the depth of the drain screw hole of different models to adapt to different specifications of wind turbine generator sets; specifically, the hollow probe 1 can be any existing telescopic rod structure that can achieve the purpose of this invention.

[0020] The negative pressure liposuction component is connected to the rear end of the hollow probe 1 to provide continuous negative pressure suction during sampling.

[0021] The positioning auxiliary tooling is used to guide the sealing sampling head into the drain screw hole at a predetermined angle and depth to ensure the consistency of the sampling position each time.

[0022] In existing pitch bearing grease sampling practices, several prominent problems commonly exist: First, hardened grease often accumulates in the drain hole channel, making it difficult for traditional straight-tube samplers to pass through smoothly; second, a large amount of non-representative grease (including unshorn new grease and long-term accumulated old grease) exists in the short channel between the drain hole and the raceway working surface. If this grease is sucked in, it will seriously contaminate the sample, leading to distorted test results; third, during pitch bearing operation, the working grease distribution on the raceway working surface is uneven, making it difficult to obtain working grease that truly reflects the bearing wear condition using traditional static sampling methods. This solution is a systematic structural design addressing these problems.

[0023] The sealed sampling head includes a central tube 2, a sliding sleeve 3, and a deformable conical umbrella head 4.

[0024] The rear end of the central tube 2 is fixedly connected to the front end of the hollow probe 1, and the open end face of the front end of the central tube 2 forms the sampling port 21.

[0025] The sliding sleeve 3 is axially slidably fitted onto the outside of the central tube 2, and the front end face of the sliding sleeve 3 is an open end face.

[0026] The deformable conical umbrella head 4 includes several conical petals 41. The rear end of each conical petal 41 is hinged to the front end of the sliding sleeve 3 through a torsion spring. Each conical petal 41 has a tendency to close inward under the action of the torsion spring. The inwardly closing conical petals 41 form a conical wrapping head that seals and wraps the sampling port 21 on the front end face of the central tube 2 inside. An isolation elastic membrane 42 is provided between each conical petal 41. When the conical petal 41 is closed, the isolation elastic membrane 42 is stretched and covers the gap between adjacent conical petals to form a continuous sealing surface. When the conical petal 41 is opened, it unfolds with the conical petal 41 to form the umbrella surface of the umbrella-shaped cover.

[0027] In the closed state, the inner wall of each conical flap 41 abuts against the outer wall of the front end of the central tube 2, completely enclosing the sampling port 21 of the central tube 2 and isolating it from the outside. On the one hand, the closed conical flap can squeeze and break the hardened grease in the channel during insertion, thus breaking the grease; on the other hand, since the sampling port 21 is completely covered, non-representative grease in the channel is blocked from the outside and cannot contact the sampling port 21, avoiding contamination.

[0028] The internal cavity of the central tube 2 is a sampling channel. One end of the sampling channel is the sampling port 21, and the other end is connected to the inner cavity of the hollow probe 1. A one-way valve is provided at the sampling port 21 to ensure that the sample can only flow in in one direction and will not flow back.

[0029] Once the sampling head reaches the predetermined depth, the pitch control module controls the pitch system to perform reciprocating pitch changes. Simultaneously, new grease is added through the grease inlet of the pitch bearing, causing the new grease to displace the working grease on the raceway working surface towards the sampling port 21. Under the combined action of the pitch driving force and the grease displacement pressure, the working grease on the raceway working surface flows. The flowing working grease generates a rearward axial thrust on the sliding sleeve 3 and the deformable conical umbrella head 4, pushing the sliding sleeve 3 to slide backward relative to the central tube 2 against the return spring force. When the sliding sleeve 3 slides backward, it causes the rear ends of each conical petal 41 to move backward. The front ends of each conical petal 41 are forced to flip outward due to the limitation of the front end outer wall of the central tube 2, forming an initial gap between the conical petal 41 and the front end of the central tube 2.

[0030] After the initial gap is formed, the pitch control module triggers the negative pressure liposuction component to start, generating negative pressure in the sampling channel and forming a liposuction flow field at the sampling port 21. The pitch control module controls the pitch system to continue reciprocating pitch and continuously injecting new liposuction. The flowing working liposuction is continuously squeezed into the interior of the conical petals 41 through the initial gap, further overcoming the torsional spring force and pushing each conical petal 41 outward, so that the deformable conical umbrella head 4 switches from the closed state to the open state, forming a forward-facing umbrella-shaped cover.

[0031] After the umbrella-shaped cover is fully opened, its larger opening faces the working surface of the raceway, and its smaller opening connects with the sampling port of the central tube 2, forming a natural flow-guiding funnel. Because the outer diameter of the umbrella-shaped cover is larger than the inner diameter of the drain screw hole, it pushes away the non-representative grease accumulated in front of the sampling port during the opening process, making the area in front of the sampling port clean. Simultaneously, the working grease driven by the pitch is collected by the umbrella-shaped cover to the sampling port, and under negative pressure, it enters the sealed grease storage assembly through the sampling channel, one-way valve, and hollow probe 1, completing the sampling. Throughout the entire process, non-representative grease never enters the sampling head, ensuring the purity of the sample.

[0032] The pitch control module communicates with the pitch control system of the wind turbine generator set, enabling precise control of the pitch system to perform reciprocating pitch changes with an amplitude of ±3° to ±10° and a frequency of 0.1Hz to 0.5Hz during the sampling process.

[0033] This pitching action serves multiple purposes: first, it causes the working grease on the raceway working surface to flow in a directional manner under shear force, breaking the static distribution of the grease; second, it works in conjunction with grease displacement to push the actual working grease on the raceway working surface (i.e., the old oil that has participated in shearing and bearing, containing wear particles and deterioration products) towards the sampling port; and third, it provides driving force for the opening of the deformable conical umbrella head 4. As mentioned earlier, the flowing working grease is squeezed into the interior of the conical petal 41 through the initial gap, pushing the conical petal 41 open.

[0034] The pitch control module is also electrically connected to the negative pressure liposuction component. It triggers the negative pressure liposuction component to start during sampling and controls the on / off of negative pressure according to a preset timing sequence to ensure the automation and standardization of the sampling process.

[0035] After sampling, the negative pressure liposuction assembly stops, the negative pressure in the sampling channel disappears, and each cone-shaped flap 41 closes inward again under the action of the torsion spring, returning to its closed state. At this time, the sampling head is withdrawn, and the closed deformable cone-shaped umbrella head 4 once again acts as an isolation mechanism, preventing residual fat in the channel from contaminating the inside of the sampling head during withdrawal. Throughout the entire sampling process, non-representative fat never enters the inside of the sampling head, ensuring the purity of the sample.

[0036] The positioning auxiliary tooling includes a threaded limit sleeve 5 and an angle alignment block 6.

[0037] The inner wall of the threaded limiting sleeve 5 has a central through hole, which passes through the threaded limiting sleeve 5 for the hollow probe 1 to pass through. The outer wall of the threaded limiting sleeve 5 has an external thread, which mates with the internal thread of the drain screw hole. During installation, the threaded limiting sleeve 5 is screwed into the drain screw hole to fix the entire positioning auxiliary fixture at the drain screw hole. The rear end face of the threaded limiting sleeve 5 forms an axial limiting surface 51, which abuts against the stepped surface 11 provided on the hollow probe 1. When the hollow probe 1 is advanced forward until the stepped surface 11 abuts against the axial limiting surface 51, the sealing sampling head reaches the predetermined depth and cannot advance further, thereby precisely controlling the depth of the sampling head into the drain screw hole and ensuring that the sampling port is located exactly near the working surface of the raceway.

[0038] Angle alignment block 6 is rotatably mounted on the outer periphery of threaded limiting sleeve 5 via connecting bearing 7. Angle alignment block 6 has a positioning key whose shape matches the shape of the angle positioning groove at the drain screw hole opening. In actual operation, firstly, the positioning key of angle alignment block 6 is aligned with and inserted into the angle positioning groove at the drain screw hole opening. At this time, the circumferential angle of angle alignment block 6 is locked and cannot rotate. Then, the threaded limiting sleeve 5 is rotated. Since angle alignment block 6 is connected to threaded limiting sleeve 5 via connecting bearing 7, threaded limiting sleeve 5 can rotate freely relative to angle alignment block 6. Therefore, the external thread of threaded limiting sleeve 5 can be smoothly screwed into the internal thread of drain screw hole, while angle alignment block 6 remains stationary, and the positioning key remains embedded in the angle positioning groove. This design ensures that the positioning auxiliary tooling has a unique circumferential angle position after installation, thereby ensuring that the sealing sampling head enters the drain screw hole at the same angle each time, and that the umbrella-shaped cover of the deformable conical umbrella head 4, after opening, can accurately face the hysteresis edge direction of the pitch bearing.

[0039] A limiting structure is provided between the central tube 2 and the sliding sleeve 3. The limiting structure includes a first limiting step on the outer wall of the central tube 2 and a second limiting step on the inner wall of the sliding sleeve 3. When the sliding sleeve 3 slides forward relative to the central tube 2 to its maximum extended position, the first limiting step and the second limiting step abut against each other, preventing the sliding sleeve 3 from sliding forward further. When the sliding sleeve 3 slides backward relative to the central tube 2 to its maximum retracted position, the rear end face of the sliding sleeve 3 abuts against the corresponding step surface on the central tube 2, preventing the sliding sleeve 3 from sliding backward further. This limiting structure ensures that the sliding sleeve 3 always slides within a predetermined stroke range, thereby ensuring that the closing and opening states of the deformable conical umbrella head 4 are within a controllable range, and that excessive sliding will not cause structural damage or functional failure.

[0040] The sealed grease storage assembly includes a sampling bottle 8, the front end of which is detachably connected to the rear end of the hollow probe 1. After sampling, the sampling bottle 8 can be removed for testing, which is convenient and quick. The negative pressure grease suction assembly includes a negative pressure pump 9 and a negative pressure tank 91. The negative pressure pump 9 is connected to the negative pressure tank 91, and the negative pressure tank 91 is connected to the rear end of the sampling bottle 8. When the negative pressure pump 9 is working, it generates negative pressure. The negative pressure tank 91 acts as a buffer and stabilizer. The negative pressure is transmitted through the sampling bottle 8 and the hollow probe 1 to the sampling channel of the sealed sampling head, providing continuous negative pressure suction for grease aspiration.

[0041] A filter screen is provided at the sampling port 21 of the central tube 2. The pore size of the filter screen is preferably 50 micrometers to 200 micrometers. During the sampling process, when the working grease enters the sampling channel through the sampling port 21, the filter screen can block larger wear particles (such as metal abrasive particles, sand particles, etc.) outside the sampling channel, allowing only smaller lubricating grease base oil and fine particles to pass through.

[0042] The wind turbine pitch bearing oil sample collection method of this embodiment, applied to the apparatus as described in any one of claims 1 to 6, includes the following steps: S1: Screw the threaded limit sleeve 5 of the positioning auxiliary tooling into the oil drain hole of the pitch bearing, and make the positioning key on the angle alignment block 6 embed into the angle positioning groove at the opening of the oil drain hole to lock the circumferential angle of the sealing sampling head. During installation, the operator first aligns the positioning key of the angle alignment block 6 with the angle positioning groove at the opening of the drain screw hole and inserts it. At this time, the circumferential angle of the angle alignment block 6 is locked and cannot be rotated. Then, the threaded limit sleeve 5 is rotated. Since the angle alignment block 6 is connected to the threaded limit sleeve 5 through the connecting bearing 7, the threaded limit sleeve 5 can rotate freely relative to the angle alignment block 6. Therefore, the external thread of the threaded limit sleeve 5 can be smoothly screwed into the internal thread of the drain screw hole, while the angle alignment block 6 remains stationary and the positioning key is always embedded in the angle positioning groove. S2: Insert the hollow probe 1 through the central through hole of the threaded limiting sleeve 5 and push it forward until the stepped surface 11 on the hollow probe 1 abuts against the rear end face of the threaded limiting sleeve 5, so that the sealed sampling head reaches the predetermined depth. At this time, each conical petal 41 of the deformable conical umbrella head 4 is in a closed state under the action of the torsion spring, and the inner wall surface of each conical petal 41 is against the front outer wall of the central tube 2, completely covering and isolating the sampling port 21; S3, the pitch control module controls the pitch system to perform reciprocating pitch, with an amplitude of ±3° to ±10° and a frequency of 0.1Hz to 0.5Hz. At the same time, new grease is added through the grease inlet of the pitch bearing, causing the new grease to displace the working grease on the raceway working surface towards the sampling port 21. The working grease on the raceway working surface flows under the combined action of the pitch driving force and the grease displacement pressure. The flowing working grease generates a backward axial thrust on the sliding sleeve 3 and the deformable conical umbrella head 4, pushing the sliding sleeve 3 to slide backward relative to the central tube 2 against the return spring force. When the sliding sleeve 3 slides backward, it causes the rear end of each conical lobe 41 to move backward. The front end of each conical lobe 41 is forced to flip outward by the limit of the front end outer wall of the central tube 2, forming an initial gap between the conical lobe 41 and the front end of the central tube 2. S4. The pitch control module triggers the negative pressure grease suction component to start, generating negative pressure in the sampling channel and forming a grease flow field at the sampling port 21. The pitch control module controls the pitch system to continue reciprocating pitch and continuously adding new grease. The flowing working grease is continuously squeezed into the conical petals 41 through the initial gap formed in step S3, further overcoming the torsional spring force to push each conical petal 41 outward, causing the deformable conical umbrella head 4 to switch from a closed state to an open state, forming a forward-facing umbrella-shaped cover. S5. After the deformable conical umbrella head 4 is fully open, its large opening faces the working surface of the raceway, and its small opening connects with the sampling port 21 of the central tube 2, forming a natural flow guide funnel. This flow guide funnel gathers the working grease driven by the pitch to the sampling port 21, and under the action of negative pressure, it enters the sealed grease storage component through the sampling channel, one-way valve, and hollow probe 1 to complete the sampling. S6. After sampling is completed, the negative pressure liposuction assembly stops, the negative pressure in the sampling channel disappears, and each cone-shaped flap 41 closes inward again under the action of the torsion spring, restoring the closed state. At this time, the sealed sampling head is withdrawn, and the closed cone-shaped umbrella head once again plays an isolation role, preventing residual grease in the channel from contaminating the inside of the sampling head during the withdrawal process.

[0043] In steps S3 and S4, the pitch control module's control of the pitch system satisfies the following timing sequence: T1 Pre-pitch Stage: The pitch coordination control module controls the pitch system to perform reciprocating pitch with an amplitude of ±3° to ±10° and a frequency of 0.1Hz to 0.5Hz for 10 to 60 seconds, causing the working grease on the raceway working surface to flow in a direction under the action of shear force. At this time, the negative pressure grease suction component has not yet been activated, nor has any new grease been added. T2 Grease Displacement Stage: Based on the T1 stage, new grease is added through the grease inlet of the pitch bearing. The injection pressure of the new grease is 2MPa to 8MPa, which displaces the working grease on the raceway working surface towards the sampling port. The flowing working grease generates a backward axial thrust on the sliding sleeve 3 and the deformable conical umbrella head 4, pushing the sliding sleeve 3 to slide backward against the return spring force, causing the rear end of the conical flap 41 to move backward. The front end of the conical flap 41 is limited by the outer wall of the front end of the central tube 2 and flips outward to form an initial gap. At this time, the negative pressure grease suction assembly has not yet been activated. T3 Joint Sampling Stage: Based on the T1 and T2 stages, the pitch control module triggers the negative pressure liposuction component to start, generating negative pressure in the sampling channel; the pitch system continues to reciprocate and continuously inject new grease, and the flowing working grease is continuously squeezed into the interior of the conical petals 41 through the initial gap formed in the T2 stage, further overcoming the torsion spring force to push each conical petal 41 outward, so that the deformable conical umbrella head 4 switches from the closed state to the open state; T4 Pressure Holding and Sampling Stage: The pitch control module maintains the continuous operation of the pitch system and the grease displacement, while the negative pressure grease suction component continues to work. The open umbrella-shaped cover gathers the working grease from the pitch displacement to the sampling port 21, and enters the sealed grease storage component under negative pressure, continuously sampling for 30 to 120 seconds. T5 Termination Stage: The pitch control module first controls the negative pressure liposuction component to stop, then stops fat displacement, and finally controls the pitch system to stop pitching.

[0044] In step T2, the grease displacement stage, the pitch control module dynamically adjusts the amplitude and frequency of the reciprocating pitch according to the real-time grease flow resistance in the sampling channel. The pitch control module obtains the real-time grease flow resistance signal in the sampling channel by monitoring the air pressure fluctuation of the negative pressure grease suction component or the axial force change of the hollow probe 1. When the grease flow resistance signal is higher than the preset upper limit of resistance, the pitch control module increases the amplitude of the reciprocating pitch to ±8° to ±10° and decreases the frequency to 0.1Hz to 0.2Hz to enhance the shear driving force on the working grease on the raceway working surface. When the grease flow resistance signal is lower than the preset lower limit of resistance, the pitch control module decreases the amplitude of the reciprocating pitch to ±3° to ±5° and increases the frequency to 0.3Hz to 0.5Hz to maintain a stable grease flow displacement speed.

[0045] In step T4, during the pressure holding and sampling stage, the pitch control module records the change curve of the grease flow resistance signal over time throughout the sampling process and identifies abnormal wear conditions of the pitch bearing based on the characteristics of the curve. When the grease flow resistance signal exhibits periodic spike pulses during the sampling process, it is determined that there are local spalling or indentation defects on the raceway working surface. The peak height of the spike pulse corresponds to the severity of the defect, and the occurrence period of the spike pulse corresponds to the rotation period of the pitch bearing. When the grease flow resistance signal shows a continuous upward trend, it is determined that there is excessive drying of grease or foreign matter intrusion on the raceway working surface. The pitch control module outputs the identification results along with the sampled data for comprehensive health assessment of the pitch bearing.

[0046] The embodiments described above are merely illustrative of specific implementations of the present invention, and while the descriptions are detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention.

Claims

1. A device for collecting oil samples from the pitch bearing of a wind turbine generator, characterized in that: Includes a hollow probe (1), a sealed sampling head, a negative pressure grease suction assembly, a sealed grease storage assembly, and a positioning auxiliary tooling; The hollow probe (1) is a segmented telescopic structure; the negative pressure liposuction assembly is connected to the rear end of the hollow probe (1); the positioning auxiliary tooling is used to guide the sealing sampling head to enter the drain screw hole at a predetermined angle and a predetermined depth; the sealing sampling head includes a central tube (2), a sliding sleeve (3) and a deformable conical umbrella head (4); the rear end of the central tube (2) is fixedly connected to the front end of the hollow probe (1), and the open end face of the front end face of the central tube (2) constitutes the sampling port (21); the sliding sleeve (3) is axially slidably fitted onto the outside of the central tube (2), and the front end face of the sliding sleeve (3) is an open end face; a return spring is provided between the sliding sleeve (3) and the central tube (2), and the return spring is always applied to make the sliding sleeve (3) relative to the central tube (2) The forward thrust of the heart tube (2); the deformable conical umbrella head (4) includes several conical valves (41), the rear end of each conical valve (41) is hinged to the front end of the sliding sleeve (3) through a torsion spring, and each conical valve (41) has a tendency to close inward under the action of the torsion spring; an isolation elastic membrane (42) is provided between each conical valve (41); in the closed state, the inner wall surface of each conical valve (41) is attached to the outer wall of the front end of the central tube (2), completely covering the sampling port (21) of the central tube (2); the internal cavity of the central tube (2) is a sampling channel, one end of the sampling channel is a sampling port (21), and the other end is connected to the inner cavity of the hollow probe (1), and a one-way valve is provided at the sampling port (21).

2. The wind turbine pitch bearing oil sampling device as described in claim 1, characterized in that: The positioning auxiliary tooling includes a threaded limiting sleeve (5) and an angle alignment block (6); the inner wall of the threaded limiting sleeve (5) is provided with a central through hole, which passes through the threaded limiting sleeve (5); the outer wall of the threaded limiting sleeve (5) is provided with an external thread, which matches the internal thread of the drain screw hole; the rear end face of the threaded limiting sleeve (5) forms an axial limiting surface (51), which is used to abut against the stepped surface (11) provided on the hollow probe (1) to limit the depth of the sealing sampling head inserted into the drain screw hole; the angle alignment block (6) is rotatably set on the outer periphery of the threaded limiting sleeve (5) through a connecting bearing (7), and the angle alignment block (6) is provided with a positioning key, which matches the shape of the angle positioning groove at the opening of the drain screw hole.

3. A wind turbine pitch bearing oil sampling device as described in claim 2, characterized in that: The data acquisition device also includes a pitch coordination control module that is communicatively connected to the pitch control system of the wind turbine generator set. The pitch coordination control module is used to control the pitch system to perform reciprocating pitch during the sampling process to promote the flow of working grease on the raceway working surface. The pitch coordination control module is also electrically connected to the negative pressure liposuction component to trigger the start of the negative pressure liposuction component during sampling.

4. A wind turbine pitch bearing oil sampling device as described in claim 1, characterized in that: A limiting structure is provided between the central tube (2) and the sliding sleeve (3). The limiting structure includes a first limiting step on the outer wall of the central tube (2) and a second limiting step on the inner wall of the sliding sleeve (3).

5. A wind turbine pitch bearing oil sampling device as claimed in claim 1, characterized in that: The sealed grease storage assembly includes a sampling bottle (8), the front end of which is detachably connected to the rear end of the hollow probe (1); the negative pressure grease suction assembly includes a negative pressure pump (9) and a negative pressure tank (91), the negative pressure pump (9) is connected to the negative pressure tank (91), and the negative pressure tank (91) is connected to the rear end of the sampling bottle (8).

6. A wind turbine pitch bearing oil sampling device as claimed in claim 1, characterized in that: A filter screen is provided at the sampling port (21) of the central tube (2).

7. A method for collecting oil samples from the pitch bearing of a wind turbine generator, applied to the apparatus described in any one of claims 1 to 6, characterized in that, Includes the following steps: S1: Screw the threaded limit sleeve (5) of the positioning auxiliary tooling into the drain screw hole of the pitch bearing, and make the positioning key on the angle alignment block (6) embed into the angle positioning groove at the opening of the drain screw hole to lock the circumferential angle of the sealing sampling head. S2: Insert the hollow probe (1) through the central through hole of the threaded limiting sleeve (5) and push it forward until the stepped surface (11) on the hollow probe (1) abuts against the rear end face of the threaded limiting sleeve (5), so that the sealed sampling head reaches the predetermined depth. S3: The pitch control module controls the pitch system to perform reciprocating pitch, and at the same time, new grease is added through the grease port of the pitch bearing, so that the new grease drives the working grease on the raceway working surface toward the sampling port (21); the working grease on the raceway working surface flows under the combined action of the pitch driving force and the grease displacement pressure. The flowing working grease generates a backward axial thrust on the sliding sleeve (3) and the deformable conical umbrella head (4), pushing the sliding sleeve (3) to overcome the return spring force and slide backward relative to the central tube (2); when the sliding sleeve (3) slides backward, it drives the rear end of each conical petal (41) to move backward, and the front end of each conical petal (41) is forced to flip outward by the limit of the front end outer wall of the central tube (2), forming an initial gap between the conical petal (41) and the front end of the central tube (2); S4: The pitch control module triggers the negative pressure liposuction component to start, generating negative pressure in the sampling channel and forming a fat flow field at the sampling port (21); the pitch control module controls the pitch system to continue reciprocating pitch and continuously injecting new fat. The flowing working fat is continuously squeezed into the interior of the cone-shaped petals (41) through the initial gap, further overcoming the torsional spring force to push each cone-shaped petal (41) outward, so that the deformable cone-shaped umbrella head (4) switches from the closed state to the open state, forming a forward-facing umbrella-shaped cover; S5. The open deformable conical umbrella head (4) gathers the working grease from the variable pitch displacement to the sampling port (21), and enters the sealed grease storage component under negative pressure to complete the sampling. S6. The negative pressure liposuction assembly stops, the negative pressure in the sampling channel disappears, and each cone-shaped flap (41) closes inward again under the action of the torsion spring, restoring the closed state and exiting the sealed sampling head.

8. A method for collecting oil samples from a wind turbine pitch bearing as described in claim 7, characterized in that, In steps S3 and S4, the pitch control module's control of the pitch system satisfies the following timing sequence: T1 Pre-pitch Stage: The pitch coordination control module controls the pitch system to perform reciprocating pitch with an amplitude of ±3° to ±10° and a frequency of 0.1Hz to 0.5Hz for 10 to 60 seconds, causing the working grease on the raceway working surface to flow in a direction under the action of shear force. At this time, the negative pressure grease suction component has not yet been activated, nor has any new grease been added. T2 Grease Displacement Stage: Based on the T1 stage, new grease is added through the grease inlet of the pitch bearing. The new grease injection pressure is 2MPa to 8MPa, which displaces the working grease on the raceway working surface towards the sampling port. The flowing working grease generates a backward axial thrust on the sliding sleeve (3) and the deformable conical umbrella head (4), pushing the sliding sleeve (3) to slide backward against the return spring force, causing the rear end of the conical flap (41) to move backward. The front end of the conical flap (41) is limited by the outer wall of the front end of the central tube (2) and flips outward to form an initial gap. At this time, the negative pressure grease suction assembly has not yet been started. T3 Joint Sampling Stage: Based on the T1 and T2 stages, the pitch control module triggers the negative pressure liposuction component to start, and negative pressure is generated in the sampling channel; the pitch system continues to reciprocate and continuously inject new grease, and the flowing working grease is continuously squeezed into the conical petal (41) through the initial gap formed in the T2 stage, further overcoming the torsion spring force to push each conical petal (41) outward, so that the deformable conical umbrella head (4) switches from the closed state to the open state; T4 Pressure Holding and Sampling Stage: The pitch control module maintains the continuous operation of the pitch system and the grease displacement, while the negative pressure grease suction component continues to work. The open umbrella-shaped cover gathers the working grease from the pitch displacement to the sampling port (21), and enters the sealed grease storage component under negative pressure, and continues to sample for 30 to 120 seconds. T5 Termination Stage: The pitch control module first controls the negative pressure liposuction component to stop, then stops fat displacement, and finally controls the pitch system to stop pitching.

9. The method for collecting oil samples from the pitch bearing of a wind turbine generator as described in claim 8, characterized in that: In step T2, the grease displacement stage, the pitch control module dynamically adjusts the amplitude and frequency of the reciprocating pitch according to the real-time grease flow resistance in the sampling channel. The pitch control module obtains the real-time grease flow resistance signal in the sampling channel by monitoring the air pressure fluctuation of the negative pressure grease suction component or the axial force change of the hollow probe (1). When the grease flow resistance signal is higher than the preset upper limit of resistance, the pitch control module increases the amplitude of the reciprocating pitch to ±8° to ±10° and decreases the frequency to 0.1Hz to 0.2Hz to enhance the shear driving force on the working grease on the raceway working surface. When the grease flow resistance signal is lower than the preset lower limit of resistance, the pitch control module decreases the amplitude of the reciprocating pitch to ±3° to ±5° and increases the frequency to 0.3Hz to 0.5Hz to maintain a stable grease flow displacement speed.

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