Long-life space bearing in-orbit operation state real-time monitoring and health maintenance device

Abstract

The invention discloses a long-life space bearing in-orbit operation state real-time monitoring and health maintenance device, and belongs to the technical field of space. According to the method, temperature field distribution characteristics are associated with bearing temperature, bearing supporting structure dependent variable, driving motor current, bearing rotating speed and air pressure change characteristics in a sealing cavity, so that a method for judging the lubricating state and operation stability of the bearing in a non-sensitive section by other signals is found; according to the method, on-orbit signal change which is not easy to find according to other signals is taken as a criterion of on-orbit fault diagnosis.

Description

TECHNICAL FIELD

[0001] The present application relates to a long-life space bearing in-orbit operation state real-time monitoring and health maintenance device, and belongs to the technical field of space. BACKGROUND

[0002] Flywheel and control moment gyro (CMG) are key executive components in satellite attitude and orbit control system, which realize the purpose of precise control of satellite attitude by exchanging momentum with satellite body. Bearing assembly is a key component of flywheel and CMG, and is also a main factor limiting the performance indicators and service life of flywheel such as the highest rotation speed. A NASA technical memorandum points out that the problem of space long-life lubrication is the main reason limiting the service life of flywheel. In the space environment of vacuum and weightlessness, lubricating oil is easy to volatilize and migrate and is lost, so that the bearing raceway cannot form an elastic fluid lubricating oil film, which accelerates the bearing wear, and in the low-speed and maneuvering working conditions, it is in an oil-poor or semi-lubricated state, which easily induces unstable operation of the retainer and increases the bearing wear, reduces the service life of the bearing, and directly leads to satellite failure or life reduction. At the same time, there also exists the phenomenon that too much lubricating oil accumulates, causing increased resistance, temperature rise and bearing failure, which is also a problem caused by the destruction of the lubricating state of the bearing.

[0003] The most effective direct solution is to supplement the oil supply or consumption, so it is of great significance to study how to realize in-orbit online monitoring, early warning and active intervention of the lubricating state of the bearing for high-reliability, high-efficiency long-life lubrication and long-life bearing.

[0004] At present, the in-orbit monitoring means of the lubricating oil distribution and operation state of the flywheel and CMG bearing at home is single, only the driving motor current and shaft temperature, which cannot make predictive judgment, and there is no technical means for immediate active intervention. The passive oil supply mode of the porous polymer oil-containing retainer capillary oil supply can ensure the service life of the bearing assembly for 3-4 years. Combined with the oil storage device (ring), the lubricating oil storage and centrifugal oil supply can be realized, which can make the service life of the bearing reach 5-8 years. The oil storage device is between the inner and outer spacer rings, and realizes passive oil supply by relying on centrifugal force and seepage-diffusion behavior of porous materials. It can be known from the analysis that under in-orbit conditions, it has the following disadvantages: as the lubricating oil is thrown out, the oil mass in the oil storage device decreases, the centrifugal force decreases, the oil supply rate decreases, and even no oil is supplied, which causes unstable oil supply; at low speed, the centrifugal force is not enough to throw out the oil, and the lubricating effect is not good. And the oil supply cannot be carried out according to the actual state of the bearing lubrication, but only the oil supply can be supplemented year by year according to the predetermined oil discharge rate. SUMMARY

[0005] The technical problem solved by the present application is to overcome the shortcomings of the prior art and provide a long-life space bearing in-orbit operation state real-time monitoring and health maintenance device, which realizes in-orbit real-time monitoring, multi-dimensional perception, information fusion, and active intervention and other measures, and carries out predictive health management closed-loop control.

[0006] The technical solution of the present application is: a long-life space bearing on-orbit operation state real-time monitoring and health maintenance device, which is installed in a flywheel sealed cavity and comprises: a mandrel located in a bearing inner ring, used for connecting two bearing inner rings and serving as a rotor connecting piece; a bearing installed on the mandrel, used for rotating a flywheel wheel body under the driving of an external motor; a bearing support structure installed between the mandrel and the bearing, used for providing device structure support and sealing protection; a multi-dimensional perception sensor cluster comprising a plurality of sensors for collecting bearing temperature, bearing support structure strain, driving motor current, bearing rotating speed, shaft temperature field distribution, and air pressure change in the flywheel sealed cavity; a control circuit installed in a flywheel line box, used for controlling the device to monitor the bearing on-orbit operation state in real time and maintain the health of the bearing; an active intervention execution module installed on the bearing support structure, used for supplementing oil mist lubrication to the bearing.

[0007] Further, the strain of the bearing support structure is measured by a strain gauge attached to the surface of the bearing support structure; the shaft temperature field distribution is imaged by an infrared probe located at the edge of the sealed cavity; the bearing temperature is collected by a thermistor attached to the bearing support structure; the driving motor current is collected by a bearing driving circuit; the bearing rotating speed is collected by an internal Hall sensor of the motor and processed by the bearing driving circuit; and the air pressure in the flywheel sealed cavity is collected by a MEMS air pressure sensor installed in the sealed cavity.

[0008] Further, when the bearing is an outer ring in motion, the bearing support structure is a mandrel; and when the bearing is an inner ring in motion, the bearing support structure is a bearing seat.

[0009] Further, the control circuit comprises: a bearing driving circuit used for driving the bearing to rotate and collecting driving motor current data and transmitting the data to a processing circuit; a sensor signal collection circuit used for collecting strain and temperature signals and transmitting the signals to the processing circuit; the processing circuit used for processing the received signals to calculate the motor rotating speed, and processing the current, strain, and temperature signals, judging the lubrication state according to the signal characteristics, and transmitting an oil supply instruction to an oil supply device control circuit; the oil supply device control circuit used for controlling a heating sheet to heat and volatilize oil according to the oil supply instruction.

[0010] Further, the active intervention execution module mainly comprises a heating sheet and a stationary oil storage ring, and the heating sheet is tightly attached to the stationary oil storage ring.

[0011] Further, the active intervention execution module comprises an oil supply device for volatilizing and supplementing lubricating oil.

[0012] Further, the oil supply device is heated by a heating sheet to volatilize the lubricating oil in the stationary polyimide porous oil storage ring.

[0013] Compared with the prior art, the present application has the following advantages: (1) The present application correlates the temperature field distribution characteristics with the bearing temperature, bearing support structure strain, driving motor current, bearing rotating speed and the air pressure change characteristics in the sealed cavity, finds the method of using other signals in the non-sensitive section to determine the bearing lubrication state and running stability, and realizes the signal change that is not easy to find on orbit, as the criterion for on-orbit fault diagnosis. (2) The present application volatilizes the lubricating oil in the internal stationary oil storage ring by heating the porous oil storage ring, and realizes the technical effect of micro-supplementing oil for the space shafting. BRIEF DESCRIPTION OF DRAWINGS

[0014] Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The accompanying drawings are included to provide a description of the preferred embodiments and are not intended to limit the scope of the application. Moreover, the same reference numerals are used throughout the same figures. In the drawings: Figure 1 Figure 1 is a structural diagram of a long-life space bearing on-orbit running state real-time monitoring and health maintenance device. DETAILED DESCRIPTION

[0015] In order to better understand the above technical solutions, the following will describe the technical solutions of the present application in detail through the accompanying drawings and specific embodiments. It should be understood that the embodiments and specific features in the embodiments are detailed descriptions of the technical solutions of the present application, and are not limitations of the technical solutions of the present application. In the case of no conflict, the technical features in the embodiments and the embodiments can be combined with each other.

[0016] The long-life space bearing on-orbit running state real-time monitoring and health maintenance device provided by the embodiments of the present application will be further described in detail below in combination with the accompanying drawings of the specification. Figure 1 The specific implementation mode can include: A mandrel is located in the bearing inner ring and is used to connect two bearing inner rings and as a rotor connecting piece. A bearing is installed on the mandrel and is used to drive the flywheel body to rotate under the driving of an external motor. A bearing support structure is installed between the mandrel and the bearing and is used to provide device structure support and sealing protection. A multi-dimensional perception sensor cluster includes a plurality of sensors for collecting bearing temperature, bearing support structure strain, driving motor current, bearing rotation speed, shaft temperature field distribution, and air pressure change in the sealed cavity of the flywheel. A control circuit is installed in the flywheel line box for controlling the device to monitor and maintain the health of the bearing in the on-orbit operation state in real time. An active intervention execution module is installed on the bearing support structure for supplementing the lubrication of the bearing with oil mist.

[0017] In the scheme provided in the embodiment of the application, specifically includes: In a vacuum and weightless space environment, the distribution and lubrication state of the bearing lubricating oil are inconsistent with those on the ground, and cannot be observed on-orbit. At present, most bearing fault diagnosis and analysis is artificially manufactured typical fault, which is not matched with the fault mode of space shaft lubrication failure and precision failure, and cannot manage the health of the space bearing on-orbit. The present application uses multi-dimensional monitoring data, information fusion, and a support vector machine method to compare, derive rules, analyze data, compare the consistency of each monitoring data, and derive a bearing lubrication state conclusion as a reference basis for on-orbit judgment.

[0018] The multi-dimensional monitoring information includes bearing temperature, bearing support structure strain, driving motor current, bearing rotation speed, shaft temperature field distribution, and air pressure change in the sealed cavity of the flywheel.

[0019] The bearing temperature, bearing support structure strain, driving motor current, bearing rotation speed, shaft temperature field distribution, and air pressure change in the sealed cavity are all-time on-orbit monitoring quantities.

[0020] The bearing support structure strain is a mandrel when the bearing is an outer ring in motion, and is a bearing seat when the bearing is an inner ring in motion.

[0021] For shaft temperature field distribution monitoring, an infrared camera imaging and image recognition method is used to correlate the temperature field distribution characteristics with the bearing temperature, bearing support structure strain, driving motor current, bearing rotation speed, and air pressure change characteristics in the sealed cavity.

[0022] The bearing support structure strain and the driving motor current are type A sensitive signals, the temperature field distribution and the bearing rotation speed are type B sensitive signals, and the bearing temperature and the air pressure change in the sealed cavity are type C sensitive signals.

[0023] The type A sensitive signal is the most sensitive, can be perceived earliest, has the best consistency between the sky and the ground, and is the first measurement to appear for bearing state discrimination.

[0024] Among them, the type B sensitive signal is analyzed as a judgment condition when the type A sensitive signal is insufficient to accurately judge the bearing lubrication state.

[0025] Among them, the type C sensitive signal is used as an auxiliary judgment mark of the type A and type B sensitive signals.

[0026] The bearing support structure strain, the driving motor current and the temperature field distribution have a wide detection range and precision that other monitoring signals do not have, and by decoupling the correlation of the above three signals and other signals when the lubrication state changes, a method for judging the bearing lubrication state and running stability of other signals in the non-sensitive section is found, which can reveal the signal changes of other signals on the track that are not easy to find, as a criterion for on-orbit fault diagnosis.

[0027] After judging the bearing lubrication state and running stability, active oil supply is used for online intervention to ensure good bearing lubrication state and running stability.

[0028] Among them, the active oil supply mode is to install a heating sheet between the bearing support structure and the stationary oil storage ring, so that the bearing temperature rises through heating, and the lubricating oil in the stationary oil storage ring volatilizes to supply micro oil to the bearing on the track.

[0029] Through the above mode, signal monitoring, data analysis, bearing on-orbit lubrication state and running stability monitoring information can be obtained, and on-orbit judgment can be made. And through active intervention, the bearing running state can be maintained, realizing the closed-loop control from monitoring, to judgment, to feedback, to realize the on-orbit bearing predictive health management system.

[0030] Obviously, those skilled in the art can make various modifications and variations to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application belong to the scope of the claims of the present application and their equivalent technologies, the present application also intends to include these modifications and variations.

[0031] The contents not described in detail in the specification of the present application are the known technology of those skilled in the art.

Claims

1. A real-time monitoring and health maintenance device for the on-orbit operation status of a long-life space bearing, installed inside the flywheel sealing cavity, characterized in that... include: The spindle, located inside the inner ring of the bearing, is used to connect the two inner rings of the bearing and as a rotor connector; The bearing, mounted on the spindle, is used to drive the flywheel body to rotate under the drive of an external motor; The bearing support structure is installed between the spindle and the bearing to provide structural support and sealing protection for the device. A multi-dimensional sensing sensor cluster includes several sensors used to collect data on bearing temperature, bearing support structure strain, drive motor current, bearing speed, shaft temperature field distribution, and air pressure changes in the flywheel sealing cavity. The control circuit, installed inside the flywheel wiring box, is used to control the device to monitor and maintain the bearing's on-rail operating status in real time. The active intervention execution module is installed on the bearing support structure and is used to provide oil mist supplemental lubrication to the bearing.

2. The device for real-time monitoring and health maintenance of the on-orbit operating status of a long-life space bearing according to claim 1, characterized in that, The strain of the bearing support structure is measured using strain gauges attached to the surface of the bearing support structure; the temperature field distribution of the shaft system is imaged using an infrared probe located at the edge of the sealed cavity; the bearing temperature is collected using a thermistor attached to the bearing support structure; the drive motor current is collected by the bearing drive circuit; the bearing speed is collected by a Hall sensor inside the motor, and the signal is processed by the bearing drive circuit; the air pressure inside the flywheel sealed cavity is collected by a MEMS air pressure sensor installed inside the sealed cavity.

3. The device for real-time monitoring and health maintenance of the on-orbit operating status of a long-life space bearing according to claim 1, characterized in that, When the bearing's outer ring moves, the bearing support structure is a spindle; when the bearing's inner ring moves, the bearing support structure is a bearing housing.

4. The device for real-time monitoring and health maintenance of the on-orbit operating status of a long-life space bearing according to claim 1, characterized in that, The control circuit includes: The bearing drive circuit is used to drive the bearing to rotate and to collect the current data of the drive motor and transmit it to the processing circuit. The sensor signal acquisition circuit is used to acquire strain and temperature signals and transmit them to the processing circuit. The processing circuit is used to process the received signals to calculate the motor speed, as well as process current, strain and temperature signals, determine the lubrication status based on the signal characteristics, and transmit the oil supply command to the oiler control circuit. The oil supply control circuit is used to control the heating element to heat the oil for evaporation according to the oil supply command.

5. The device for real-time monitoring and health maintenance of the on-orbit operating status of a long-life space bearing according to claim 1, characterized in that, The active intervention execution module mainly includes a heating element and a stationary oil storage ring, with the heating element in close contact with the stationary oil storage ring.

6. The device for real-time monitoring and health maintenance of the on-orbit operating status of a long-life space bearing according to claim 1, characterized in that, The active intervention execution module includes an oiler, which is used to evaporate the lubricating oil and replenish it.

7. The device for real-time monitoring and health maintenance of the on-orbit operating status of a long-life space bearing according to claim 6, characterized in that, The oil supply device consists of a heating element that heats a porous oil storage ring made of oil-containing static polyimide.

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