A kind of shaft end temperature testing device for double-fed motor rotor

Abstract

The application relates to a shaft end temperature testing device for a doubly-fed motor rotor, which comprises a cover on a motor and a rotating shaft connected with a motor rotor, the middle part of the cover is connected with an extension pipe matched with the rotating shaft, the top end of the extension pipe is rotationally connected with an auxiliary sleeve sleeved on the rotating shaft, and an auxiliary testing ring matched with the auxiliary sleeve is embedded and installed on the inner wall of the extension pipe; a wiring fixing ring and an auxiliary temperature detector are installed on the auxiliary testing ring; a plurality of uniformly distributed heat conduction sheets are embedded and connected on the rotating shaft, and a temperature measuring optical fiber is arranged in the rotating shaft; one end of the extension pipe away from the auxiliary sleeve is connected with a sealing bearing matched with the rotating shaft, an oil injection ring embedded on the inner wall of the extension pipe and used for inputting and outputting heat conducting oil is arranged between the sealing bearing and the auxiliary sleeve, real-time and accurate monitoring and dynamic protection of the shaft end temperature of the doubly-fed motor rotor are realized, and stable transmission of testing data and reliable operation of the device under high-speed rotating working conditions are ensured.

Description

Technical Field

[0001] This invention relates to a rotor temperature testing device, and more particularly to a shaft end temperature testing device for a doubly fed motor rotor, applicable to the field of temperature testing devices. Background Technology

[0002] During routine use, electric motors require temperature testing to determine if their operation is normal. Existing shaft-end temperature testing devices for doubly-fed motor rotors primarily monitor temperature in real time by installing temperature sensors at specific locations on the shaft end. These devices typically feature high-precision temperature probes that quickly and accurately detect shaft-end temperature changes and transmit the data to a matching display and recording module. Their compact structure allows them to fit into the relatively small and complex internal space of a doubly-fed motor.

[0003] Chinese patent CN116633087B discloses a motor shaft end temperature testing sensor, which includes a rotor fixture for fixed connection with the motor output shaft; a contact temperature measuring element is disposed inside the motor; a magnetoelectric device is disposed between the stator fixture and the rotor fixture, and the magnetoelectric device is used to power the signal transmission module. The temperature measuring element of this invention is directly connected to the inside of the motor, has low susceptibility to external environmental variables, and provides accurate measurement results.

[0004] Chinese patent CN109520639B discloses a device for online monitoring of the connecting rod temperature of an emergency diesel generator, including a fixing plate, an oil collection part, and a temperature sensor. This invention can collect the oil slicked off the connecting rod of an emergency diesel generator and monitor the oil temperature in real time, thereby indirectly monitoring the operating status of the connecting rod and improving the reliability of status monitoring and the safety of unit operation of the emergency diesel generator set.

[0005] The temperature detection components of existing shaft end temperature testing devices are prone to aging or damage under continuous high temperature environments. Furthermore, existing shaft end temperature testing devices do not readily assist in cooling the rotor shaft. The continuous high temperature at the rotor shaft end of a doubly fed motor may cause malfunctions in the temperature detection components and accelerate their aging. Summary of the Invention

[0006] In view of the above-mentioned prior art, the technical problem to be solved by the present invention is that the temperature detection component of the existing shaft end temperature testing device is prone to aging or damage under continuous high temperature environment.

[0007] To solve the above problems, the present invention provides a shaft end temperature testing device for a doubly fed motor rotor, including an end cover on the motor and a rotating shaft connected to the motor rotor. An extension tube matching the rotating shaft is connected to the middle of the end cover, and an auxiliary sleeve sleeved on the rotating shaft is rotatably connected to the top of the extension tube. An auxiliary test ring matching the auxiliary sleeve is embedded in the inner wall of the extension tube.

[0008] The auxiliary test ring is equipped with a wiring lock ring and an auxiliary temperature detector;

[0009] Multiple evenly distributed heat-conducting plates are embedded in the rotating shaft, and a temperature-sensing optical fiber is threaded inside the rotating shaft.

[0010] The end of the extension tube away from the auxiliary sleeve is connected to a sealed bearing that matches the rotating shaft. An oil injection ring is embedded in the inner wall of the extension tube and used for the input and output of heat transfer oil between the sealed bearing and the auxiliary sleeve. An oil guide tube that communicates with the oil injection ring is embedded in the inner side of the end cap.

[0011] The auxiliary sleeve includes a conductive slip ring rotatably connected to the fixed ring of the wiring, and an insulating bushing fixedly connected to the conductive slip ring and sleeved on the rotating shaft. The inner wall of the insulating bushing is provided with a wiring groove for wiring with the temperature measuring fiber optic cable, and an electrical connection to the conductive slip ring is installed in the wiring groove.

[0012] As a further supplement to this application, the oil guide pipes are configured as a pair and connected to the input and output ends of the oil injection ring respectively, and a circulating fluid pump is connected between the two oil guide pipes.

[0013] As a further supplement to this application, the motor is connected to an air-cooling device, the output end of which is connected to the inner space of the end cover.

[0014] As a further supplement to this application, a thermal expansion column is connected between the wiring ring and the inner wall of the extension tube. The thermal expansion column includes a hollow heat-conducting cylinder and a piston rod inserted therein. A certain amount of thermal expansion liquid is sealed and stored inside the hollow heat-conducting cylinder. The end of the piston rod located outside the hollow heat-conducting cylinder is fixedly connected to the wiring ring.

[0015] As a further supplement to this application, a non-contact temperature sensor for detecting the shaft temperature is connected to the auxiliary temperature detector. Before the oil ring outputs heat transfer oil, the non-contact temperature sensor performs non-contact temperature detection on the shaft.

[0016] As a further supplement to this application, the length range of the heat-conducting sheet covers conductive slip rings and sealed bearings.

[0017] Both the fixed ring and the conductive slip ring are provided with at least two annular conductors, and the distance between the two annular conductors is greater than their own thickness.

[0018] As a further supplement to this application, a heat insulation plate is installed at the bottom of the inner wall of the insulating bushing, and a storage battery and a wireless signal transmitting unit are installed on the heat insulation plate. The temperature measuring optical fiber is electrically connected to the storage battery and the wireless signal transmitting unit.

[0019] As a further supplement to this application, an auxiliary temperature measurement system is also included, comprising a data acquisition module, a data processing module, a control module, and a data storage module; the data acquisition module is used to acquire temperature test data of the rotating shaft and status data of its associated equipment; the data processing module is used to process and analyze the data acquired by the data acquisition module and generate control commands; the control module drives the execution components to move according to the decision commands of the data processing module; and the data storage module is used to store temperature detection data, control commands, and system status parameters.

[0020] In summary, real-time, accurate monitoring and dynamic protection of the rotor shaft end temperature of a doubly-fed motor have been achieved, ensuring stable transmission of test data and reliable operation of the device under high-speed rotation conditions. Through the synergistic effect of the temperature-sensing fiber optic cable and auxiliary temperature detector, combined with the heat transfer oil circulation via the oil injection ring, a rapid response is achieved when the shaft temperature overheats, effectively reducing the impact of thermal stress on the shaft and temperature sensing elements, thereby avoiding performance degradation or failure of the temperature sensing elements due to overheating; and it is easy to extend the service life of the device. Attached Figure Description

[0021] Figure 1 These are perspective views of the first and second embodiments of this application;

[0022] Figure 2 These are exploded views of the first and second embodiments of this application without the auxiliary cover.

[0023] Figure 3 This is a perspective view of the inner side of the end cap according to the first and second embodiments of this application;

[0024] Figure 4 This is a cross-sectional view of the first embodiment of this application;

[0025] Figure 5 for Figure 4 Schematic diagram of the structure at point A;

[0026] Figure 6 This is a partial cross-sectional view of the wiring fixed ring and the conductive slip ring when separated according to the second embodiment of this application;

[0027] Figure 7 This is a partial cross-sectional view of the auxiliary sleeve in the third embodiment of this application;

[0028] Figure 8 This is the system block for the fourth embodiment of this application.

[0029] Explanation of the labels in the diagram:

[0030] 1. End cap; 11. Extension tube; 12. Oil guide tube; 2. Shaft; 21. Heat-conducting plate; 22. Temperature measuring fiber optic cable; 3. Auxiliary sleeve; 31. Conductive slip ring; 32. Insulating bushing; 33. Battery; 4. Auxiliary test ring; 41. Wiring fixing ring; 42. Auxiliary temperature detector; 43. Thermal expansion column; 5. Sealed bearing; 6. Oil injection ring. Detailed Implementation

[0031] The four embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0032] Implementation method 1:

[0033] Figure 1 - Figure 5 A shaft end temperature testing device for a doubly fed motor rotor is shown, including an end cover 1 on the motor and a rotating shaft 2 connected to the motor rotor. An extension tube 11 matching the rotating shaft 2 is connected to the middle of the end cover 1. An auxiliary sleeve 3 sleeved on the rotating shaft 2 is rotatably connected to the top of the extension tube 11. An auxiliary test ring 4 matching the auxiliary sleeve 3 is embedded in the inner wall of the extension tube 11.

[0034] The auxiliary test ring 4 is equipped with a wiring ring 41 and an auxiliary temperature detector 42. The auxiliary test ring 4 is connected to the signal of an external test system. The auxiliary temperature detector 42 is connected to a fluid temperature sensor for detecting the temperature of the heat transfer oil.

[0035] Multiple uniformly distributed heat-conducting plates 21 are embedded and connected on the rotating shaft 2. The length of the heat-conducting plates 21 covers the conductive slip ring 31 and the sealed bearing 5. A temperature-sensing optical fiber 22 is inserted inside the rotating shaft 2. The temperature-sensing optical fiber 22 is used to detect the temperature of the rotating shaft 2 in real time. The temperature-sensing optical fiber 22 is embedded inside the rotating shaft 2, which is not easily affected by the external environment and the measurement results are accurate.

[0036] The end of the extension tube 11 away from the auxiliary sleeve 3 is connected to a sealed bearing 5 that matches the rotating shaft 2. An oil injection ring 6 is embedded in the inner wall of the extension tube 11 and used for the input and output of heat transfer oil between the sealed bearing 5 and the auxiliary sleeve 3. An oil guide tube 12 that communicates with the oil injection ring 6 is embedded in the inner side of the end cap 1. The oil guide tubes 12 are configured as a pair and are respectively connected to the input end and the output end of the oil injection ring 6. A circulating liquid pump is connected between the two oil guide tubes 12. The oil injection ring 6 is used to transport and discharge oil through the circulating liquid pump and the oil guide tube 12. When the temperature measuring fiber optic 22 detects that the temperature of the rotating shaft 2 is higher than the set threshold, the circulating liquid pump works to inject heat transfer oil into the gap between the sealed bearing 5 and the conductive slip ring 31 through the oil injection ring 6. The heat transfer oil provides overheat protection for the rotating shaft 2.

[0037] At this time, the temperature of the heat transfer oil is detected by the auxiliary temperature detector 42. Based on the detected temperature change of the heat transfer oil and the detected temperature of the rotating shaft 2, the circulation flow rate of the heat transfer oil is adjusted to cool down the rotating shaft 2 and prevent the rotating shaft 2 from overheating and affecting the service life of the temperature measuring fiber 22.

[0038] The auxiliary sleeve 3 includes a conductive slip ring 31 rotatably connected to the wiring ring 41. Both the wiring ring 41 and the conductive slip ring 31 are provided with at least two annular conductors, and the distance between the two annular conductors is greater than their own thickness. Under normal conditions, the annular conductor on the wiring ring 41 is in contact with one annular conductor on the conductive slip ring 31 and slides relative to each other. The end of the conductive slip ring 31 near the sealing bearing 5 is provided with a sealing ring that rotates and seals with the extension tube 11.

[0039] An insulating sleeve 32 is fixedly connected to the conductive slip ring 31 and sleeved on the rotating shaft 2. The inner wall of the insulating sleeve 32 is provided with a wiring groove for wiring with the temperature measuring optical fiber 22. A wiring unit that is electrically connected to the conductive slip ring 31 is installed in the wiring groove. After the temperature measuring optical fiber 22 is wired to the wiring unit, it is electrically connected to the conductive slip ring 31, so that the detection data of the temperature measuring optical fiber 22 can be transmitted to the external system through the wiring ring 41.

[0040] A cooling device (not shown in the figure) is connected to the motor. The output end of the cooling device is connected to the inner space of the end cover 1. The cooling device cools the end cover 1 as a whole to help cool the shaft 2. The installation is carried out by a person skilled in the art by selecting a suitable cooling device from the prior art. The cooling device is an optional auxiliary component.

[0041] In this embodiment, the rotating shaft 2 rotates continuously with the doubly-fed motor rotor. The auxiliary sleeve 3, through the cooperation of the conductive slip ring 31 and the wiring fixed ring 41, achieves a stable signal connection between the temperature-sensing optical fiber 22, the auxiliary temperature detector 42, and the external testing system during the rotation of the rotating shaft 2. The heat-conducting plates 21 are evenly distributed on the rotating shaft 2, effectively improving the heat conduction efficiency, enabling the temperature-sensing optical fiber 22 to more accurately detect the actual temperature of the rotating shaft 2.

[0042] When the temperature-sensing fiber optic cable 22 detects an abnormal temperature rise in the shaft 2, the circulating fluid pump quickly starts, delivering heat transfer oil to the oil injection ring 6 through the oil guide pipe 12. The heat transfer oil is injected into the gap between the sealed bearing 5 and the conductive slip ring 31. Utilizing the excellent thermal conductivity of the heat transfer oil and its flow through the heat-conducting plate 21 to enhance heat exchange, the heat on the shaft 2 is quickly removed, achieving effective overheat protection for the shaft 2. Simultaneously, the auxiliary temperature detector 42 continuously monitors the temperature change of the heat transfer oil and dynamically adjusts the circulation rate of the heat transfer oil based on the monitoring results to ensure optimal cooling effect.

[0043] The design of the insulating bushing 32 not only ensures the stability of the electrical connection between the temperature measuring fiber 22 and the conductive slip ring 31, but also effectively isolates the electrical parts from the mechanical parts of the rotating shaft 2, thereby improving the safety and reliability of the entire testing device.

[0044] This embodiment achieves real-time, accurate monitoring and dynamic protection of the rotor shaft end temperature of the doubly fed motor, ensuring stable transmission of test data and reliable operation of the device under high-speed rotation conditions. Through the synergistic effect of the temperature-sensing fiber optic cable 22 and the auxiliary temperature detector 42, combined with the oil injection ring 6 for heat transfer oil circulation, it responds quickly when the shaft 2 temperature is overheated, effectively reducing the impact of thermal stress on the shaft 2 and the temperature sensing element (temperature-sensing fiber optic cable 22), thereby avoiding performance degradation or failure of the temperature sensing element due to overheating; and easily improving the service life of the device.

[0045] The second implementation method:

[0046] The difference between this implementation method and the first implementation method is that:

[0047] Figure 6 As shown, a thermal expansion column 43 is connected between the wiring ring 41 and the inner wall of the extension tube 11. The thermal expansion column 43 includes a hollow heat-conducting cylinder and a piston rod inserted therein. A certain amount of thermal expansion liquid is sealed and stored inside the hollow heat-conducting cylinder. One end of the piston rod located outside the hollow heat-conducting cylinder is fixedly connected to the wiring ring 41. The wiring ring 41 is connected to the auxiliary temperature detector 42 through an elastic wire.

[0048] When the hollow heat-conducting cylinder overheats, the temperature of the heat-conducting oil is higher than the set threshold of the temperature-measuring optical fiber 22 in the first embodiment. The thermal expansion fluid expands due to heat, which in turn pushes the piston rod to move, causing the annular conductor of the wiring ring 41 and the conductive slip ring 31 to separate from each other, thereby de-energizing the conductive slip ring 31. The temperature at which the thermal expansion column 43 triggers the de-energization of the conductive slip ring 31 is higher than the set temperature threshold for triggering the injection of heat-conducting oil.

[0049] To avoid accelerating oxidation of the electrical contact surface of the ring conductor due to rotational friction at high temperatures, to prevent a decrease in the conductivity of the ring conductor, and to prevent the temperature sensing fiber optic cable 22 from operating at continuous high temperatures, which would affect its service life.

[0050] It should be noted that before the piston rod moves to separate the wiring ring 41 from the conductive slip ring 31, the oil injection ring 6 has already injected heat transfer oil into the gap between the sealed bearing 5 and the conductive slip ring 31. The appropriate type and dosage of thermal expansion fluid from the prior art should be selected by those skilled in the art for setting; for example: dimethyl silicone oil; the dosage is determined according to the volume of the hollow heat transfer cylinder (for example, 10ml cylinder corresponds to 5ml liquid), to ensure that when the heat transfer oil is injected and further overheated, the expansion amount of the thermal expansion fluid is sufficient to drive the piston rod to a standard displacement distance (such as 2mm) or more, ensuring reliable separation of the wiring ring 41 and the conductive slip ring 31.

[0051] If the temperature of the rotating shaft 2 continues to rise while it is dissipating heat through the heat transfer oil, the heat expansion fluid in the thermal expansion column 43 will expand to the point that it pushes the wiring ring 41 to disconnect from the conductive slip ring 31. The operation of the temperature measuring fiber 22 will be suspended by disconnecting the electrical connection of the conductive slip ring 31.

[0052] Optionally, a non-contact temperature sensor for detecting the temperature of the rotating shaft 2 is connected to the auxiliary temperature detector 42. After the wiring ring 41 is disconnected from the conductive slip ring 31, the temperature of the heat transfer oil is detected by the fluid temperature sensor to assist in determining the temperature of the rotating shaft 2. Before the heat transfer oil is input, the non-contact temperature sensor can be controlled to assist in detecting the temperature of the rotating shaft 2. The non-contact temperature sensor is an optional sensor.

[0053] In normal use, the temperature of the rotating shaft 2 is detected by the temperature-sensing optical fiber 22. When the rotating shaft 2 overheats, heat-conducting oil is first introduced into the rotating shaft 2 through the oil injection ring 6 of the first embodiment to cool the rotating shaft 2. When the temperature of the rotating shaft 2 rises further, the connection fixing ring 41 is disconnected from the conductive slip ring 31 by the thermal expansion column 43 to protect the annular conductor and the temperature-sensing optical fiber 22 and prevent them from working continuously under excessively high temperature conditions and thus accelerating aging.

[0054] The third implementation method:

[0055] The difference between this embodiment and the first and second embodiments is that:

[0056] Figure 7 As shown, a heat insulation plate is installed at the bottom of the inner wall of the insulating bushing 32. The battery 33 and the wireless signal transmitting unit are installed on the heat insulation plate. The heat insulation plate is used to isolate the high temperature of the rotating shaft 2 and reduce the impact of the high temperature of the rotating shaft 2 on the battery 33 and the wireless signal transmitting unit.

[0057] The temperature-measuring optical fiber 22 is electrically connected to the battery 33 and the wireless signal transmitting unit. The battery 33 is electrically connected to the conductive slip ring 31 via a charging cable. The wiring ring 41 is connected to the external power supply system. A switch is connected to the wiring ring 41 to control its power supply. The battery 33 and the wireless signal transmitting unit are optional installation items.

[0058] During normal operation, the temperature-sensing fiber optic cable 22 detects the temperature of the rotating shaft 2 in real time and transmits the detected temperature data to the external testing system through the wireless signal transmission unit; while the battery 33 is used to power the temperature-sensing fiber optic cable 22. When the rotating shaft 2 is not working, or when the temperature of the rotating shaft 2 is within the set safe temperature range, and the battery 33 has a charge lower than the set value, the wiring ring 41 can be energized by using an on / off switch, and the battery 33 can be charged through the conductive slip ring 31 and the charging cable.

[0059] Compared with the first and second implementation methods, in this implementation method, the temperature measuring fiber 22 is independently embedded in the rotating shaft 2, eliminating the need to keep the temperature measuring fiber 22 connected to the external line in real time, thus realizing wireless transmission of temperature measurement data and improving the ease of use and flexibility of the testing device.

[0060] The fourth implementation method:

[0061] Figure 8 This solution also includes an auxiliary temperature measurement system, which comprises a data acquisition module, a data processing module, a control module, and a data storage module.

[0062] The data acquisition module is used to collect temperature test data of the rotating shaft 2. The temperature measuring fiber optic cable 22 and the auxiliary temperature detector 42 are both connected to the data acquisition module for signal transmission. If an air-cooling device is installed, the data acquisition module can also collect the temperature of the air-cooling outlet.

[0063] The data acquisition module can also collect status data of its associated equipment, specifically including: collecting status parameters of the heat transfer oil circulation system, such as the operating rate of the circulating liquid pump (via a speed sensor or flow sensor) and the flow rate of the heat transfer oil (indirectly reflecting the circulation rate).

[0064] Collect battery power data to help determine whether charging mode needs to be activated.

[0065] The data processing module is used to process and analyze the data collected by the data acquisition module and generate control commands;

[0066] Specific tasks include:

[0067] Temperature threshold judgment and protection trigger: Real-time comparison of the temperature of shaft 2 with the set threshold: If it is higher than the threshold, trigger the first-level protection and control the circulation pump to start injecting heat transfer oil (as in the first implementation).

[0068] The heat transfer oil circulation rate is adjusted based on the "real-time shaft temperature" and the "temperature change of the heat transfer oil," and an adjustment command is output to the control module, such as increasing or decreasing the speed of the circulating fluid pump. When adjusting the heat transfer oil circulation rate, the optimal heat transfer oil circulation rate is calculated according to a preset algorithm. The specific algorithm is set by those skilled in the art based on existing technology, such as analyzing the optimal heat transfer oil circulation rate through PID algorithm or fuzzy control algorithm.

[0069] The data processing module can also calculate the temperature of the shaft 2 by means of the mapping relationship between the heat transfer oil temperature and the shaft temperature after the conductive slip ring 31 is disconnected (second embodiment). The mapping relationship is modeled by those skilled in the art based on historical temperature detection data. The temperature of the heat transfer oil detected by the fluid temperature sensor is used to calculate the temperature of the shaft 2 to ensure the continuity of temperature monitoring in non-contact state.

[0070] The control module drives the execution components to perform actions based on the decision instructions from the data processing module, thereby achieving overheat protection and temperature regulation for the rotating shaft 2.

[0071] Specific tasks include:

[0072] Heat transfer oil circulation system control: Upon receiving the "shaft temperature exceeds threshold" command, control the circulation pump to start and inject heat transfer oil into the space between the sealed bearing 5 and the conductive slip ring 31 through the oil injection ring 6;

[0073] Based on the "optimal circulation rate" output by the data processing module, the speed of the circulating liquid pump is adjusted to change the flow rate of the heat transfer oil, thereby achieving dynamic cooling.

[0074] Once the temperature of shaft 2 drops to a safe range, control the circulating liquid pump to stop or reduce its rate to avoid overcooling.

[0075] Battery 33 charging control (adapted to the third implementation method).

[0076] The battery 33 power level is monitored (input via data acquisition module). When the power level is lower than the set value and the rotating shaft 2 is in a non-working state or within a safe temperature range, the on / off switch is controlled to open and close, and the battery 33 is charged through the conductive slip ring 31 and the charging cable. After charging is completed, the on / off switch is automatically disconnected to avoid overcharging.

[0077] The data storage module is used to store temperature detection data, control commands, and system status parameters; the data storage module supports external devices reading the stored data.

[0078] The auxiliary temperature measurement system enables real-time monitoring, dynamic cooling adjustment, and safety protection of the rotor shaft end temperature of the doubly fed motor.

[0079] In light of current practical needs, the above-described embodiments adopted in this application are not limited to these. Any changes made within the scope of knowledge possessed by those skilled in the art without departing from the concept of this application still fall within the protection scope of this invention.

Claims

1. A shaft end temperature testing device for a doubly fed motor rotor, comprising an end cover (1) on the motor and a rotating shaft (2) connected to the motor rotor, characterized in that: The end cap (1) is connected to an extension tube (11) that matches the rotating shaft (2) at the middle part. An auxiliary sleeve (3) that is sleeved on the rotating shaft (2) is rotatably connected to the top of the extension tube (11). An auxiliary test ring (4) that matches the auxiliary sleeve (3) is embedded in the inner wall of the extension tube (11). The auxiliary test ring (4) is equipped with a wiring ring (41) and an auxiliary temperature detector (42), and the auxiliary temperature detector (42) is connected to a fluid temperature sensor for detecting the temperature of the heat transfer oil. Multiple uniformly distributed heat-conducting plates (21) are embedded and connected on the rotating shaft (2), and a temperature-measuring optical fiber (22) is inserted inside the rotating shaft (2); a sealed bearing (5) matching the rotating shaft (2) is connected to one end of the extension tube (11) away from the auxiliary sleeve (3); an oil injection ring (6) embedded in the inner wall of the extension tube (11) and used for the input and output of heat-conducting oil is provided between the sealed bearing (5) and the auxiliary sleeve (3); an oil guide tube (12) communicating with the oil injection ring (6) is embedded and installed inside the end cap (1); The auxiliary sleeve (3) includes a conductive slip ring (31) rotatably connected to the wiring ring (41). An insulating bushing (32) is fixedly connected to the conductive slip ring (31) and sleeved on the rotating shaft (2). A wiring groove for wiring to the temperature measuring optical fiber (22) is opened on the inner wall of the insulating bushing (32). A wiring unit electrically connected to the conductive slip ring (31) is installed in the wiring groove.

2. The shaft end temperature testing device for a doubly-fed motor rotor according to claim 1, characterized in that: The oil guide pipes (12) are configured as a pair and are respectively connected to the input end and the output end of the oil injection ring (6). A circulating liquid pump is connected between the two oil guide pipes (12).

3. The shaft end temperature testing device for a doubly-fed motor rotor according to claim 1, characterized in that: The motor is connected to a wind-cooling device, and the output end of the wind-cooling device is connected to the inner space of the end cover (1).

4. The shaft end temperature testing device for a doubly-fed motor rotor according to claim 1, characterized in that: A thermal expansion column (43) is connected between the wiring ring (41) and the inner wall of the extension tube (11). The thermal expansion column (43) includes a hollow heat-conducting cylinder and a piston rod inserted therein. A certain amount of thermal expansion liquid is sealed and stored inside the hollow heat-conducting cylinder. One end of the piston rod located outside the hollow heat-conducting cylinder is fixedly connected to the wiring ring (41).

5. The shaft end temperature testing device for a doubly-fed motor rotor according to claim 4, characterized in that: The auxiliary temperature detector (42) is connected to a non-contact temperature sensor for detecting the temperature of the rotating shaft (2). Before the oil injection ring (6) outputs heat transfer oil, the non-contact temperature sensor performs non-contact temperature detection on the rotating shaft (2).

6. The shaft end temperature testing device for a doubly-fed motor rotor according to claim 1, characterized in that: The length of the heat-conducting sheet (21) covers the conductive slip ring (31) and the sealed bearing (5).

7. The shaft end temperature testing device for a doubly-fed motor rotor according to claim 1, characterized in that: Both the fixed ring (41) and the conductive slip ring (31) are provided with at least two annular conductors, and the distance between the two annular conductors is greater than their own thickness.

8. The shaft end temperature testing device for a doubly-fed motor rotor according to claim 1, characterized in that: A heat insulation plate is installed at the bottom of the inner wall of the insulating bushing (32), and a storage battery (33) and a wireless signal transmitting unit are installed on the heat insulation plate. The temperature measuring optical fiber (22) is electrically connected to the storage battery (33) and the wireless signal transmitting unit.

9. A shaft end temperature testing device for a doubly-fed motor rotor according to any one of claims 1-8, characterized in that: It also includes an auxiliary temperature measurement system, which includes a data acquisition module, a data processing module, a control module, and a data storage module. The data acquisition module is used to collect temperature test data of the rotating shaft (2) and status data of its associated equipment. The data processing module is used to process and analyze the data collected by the data acquisition module and generate control commands. The control module drives the execution component to move according to the decision commands of the data processing module. The data storage module is used to store temperature detection data, control commands, and system status parameters.

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