An aero-engine rotor speed casing external detection device

Abstract

The utility model relates to aero -engine state monitoring and refitting technical field, especially an aero -engine rotor rotating speed's machine case external detection device, including fixed on the interface adaptation seat of engine machine case spare interface, install in the interface adaptation seat with the drive gear of original gear meshing in the engine inside, transmission main shaft with drive gear fixed connection, the bearing seat casing and end cover that are equipped with a pair of support bearing inside, end cover sets up in bearing seat casing open end, support bearing is used for supporting transmission main shaft, still include the trigger gear disc, bearing seat casing is fixedly connected with interface adaptation seat, the end of transmission main shaft stretches out end cover, and it is installed with trigger gear disc at its end, bearing seat casing is provided with the sensor support for installing sensor, the utility model effectively eliminates the deviation, drift and delay phenomenon of rotating speed signal, can directly utilize engine existing spare interface and install, need not to carry out structural change to engine ontology.

Description

Technical Field

[0001] This utility model relates to the field of aircraft engine condition monitoring and modification technology, and in particular to an external casing detection device for aircraft engine rotor speed. Background Technology

[0002] The rotor speed of an aero-engine is one of the key parameters for monitoring its operating status, controlling fuel supply, and ensuring safe operation. In the original design of modern aero-engines, sensor interfaces for measuring high and low pressure rotor speeds are usually integrated. However, many aero-engines currently used in specific projects (such as ground power generation and industrial drives) have core designs that originated in the mid-20th century. Their speed measurement systems are mostly based on analog signal technology. This traditional analog speed measurement system has problems such as easy signal attenuation, weak anti-interference ability, and the need for complex secondary conversion. It is difficult to interface directly and efficiently with modern digital control systems (such as vehicle or engine control units), which brings significant inconvenience to current product development and technical modification.

[0003] In existing technologies, a common improvement approach to address the aforementioned problems is to utilize existing spare interfaces on the engine casing, such as generator mounting interfaces. Specifically, a short shaft is added to this interface, meshing with the gear train inside the engine. This allows the rotor to rotate and exit the casing, where the rotational speed signal is acquired by reading the gear engagement sensor (such as a laser speed sensor). While this method achieves some degree of speed signal extraction, its transmission chain structure is typically simple, lacking targeted precision support and sealing design. This similar implementation has several significant drawbacks: First, the support rigidity of the transmission shaft system is insufficient and... The large connection gaps can cause deviations and drifts in the transmitted speed signal, making it impossible to accurately reflect the precise speed of the engine rotor. Secondly, the simple structure results in elastic deformation and response lag during transmission, causing noticeable delays in the data read and failing to meet the requirements for real-time and precise control. Finally, the solution does not adequately consider sealing, reliability, and long-term stability. Under harsh operating conditions of high speed, high temperature, and high vibration, it is prone to problems such as lubrication leakage, contaminant intrusion, or premature wear, which not only affect measurement accuracy but may also threaten the operational safety of the engine itself, while also bringing additional difficulties to subsequent overall layout and maintenance.

[0004] Therefore, in response to the problems of poor transmission chain rigidity and gaps in the existing devices, which lead to signal deviation and delay, as well as insufficient sealing and reliability, which easily cause leakage and wear under harsh operating conditions, threatening engine safety and increasing maintenance burden, an external casing detection device for the rotor speed of aero-engines can be designed. This device can directly, in real time and accurately read the rotor speed of the engine, and is an external detection device with high reliability and easy modification. Utility Model Content

[0005] To overcome the problems of poor rigidity and gaps in the transmission chain of existing devices, which lead to signal deviation and delay; at the same time, their insufficient sealing and reliability make them prone to leakage and wear under harsh operating conditions, threatening engine safety and increasing maintenance burden.

[0006] The technical solution of this utility model is as follows: an external casing detection device for the rotor speed of an aero-engine, comprising an interface adapter fixed to a spare interface on the engine casing, a drive gear installed in the interface adapter and meshing with the original gear inside the engine, a transmission main shaft fixedly connected to the drive gear, a bearing housing housing and an end cover containing a pair of support bearings, the end cover being located at the open end of the bearing housing housing, the support bearings being used to support the transmission main shaft, and a trigger gear plate being included. The bearing housing housing is fixedly connected to the interface adapter, the end of the transmission main shaft extends out of the end cover, and a trigger gear plate is installed at its end. A sensor bracket for mounting a sensor is provided on the bearing housing housing.

[0007] Preferably, when the engine rotor rotates, the original gear in the spare interface is driven to rotate through the internal gear system. After meshing with the drive gear of this device, the rotational motion is transmitted to the transmission main shaft. The transmission main shaft rotates smoothly and accurately in the bearing housing supported by high-precision bearings and transmits the motion to the outside of the casing. The trigger gear plate fixed to the end of the transmission main shaft rotates synchronously at high speed. The speed sensor mounted on the sensor bracket can generate a pulse signal that strictly corresponds to the engine rotor speed by detecting the passing frequency of the trigger gear plate teeth or slots, thereby realizing direct and real-time reading of the speed.

[0008] Preferably, a sealing gasket is provided between the interface adapter and the interface flange of the engine casing.

[0009] Preferably, the drive gear and the transmission shaft are connected by a spline or interference fit.

[0010] Preferably, the support bearings are paired angular contact ball bearings.

[0011] Preferably, the end cap has a sealing structure inside.

[0012] Preferably, the sealing structure is a lip seal or a labyrinth seal.

[0013] Preferably, the trigger gear is an involute gear or an equally spaced slotted disc.

[0014] The beneficial effects of this utility model are as follows: It employs a high-rigidity transmission shaft system and high-precision bearing support, significantly reducing clearance and deformation in the transmission chain, effectively eliminating deviations, drift, and delays in the speed signal. It connects to the engine via a standardized interface adapter and utilizes a professional end-cap sealing design, ensuring both installation alignment and accuracy while maintaining the original sealing performance of the engine casing. As an independent modular unit, it can be directly installed using the engine's existing spare interfaces without requiring structural modifications to the engine body, making it particularly suitable for the modernization of older engines. All key transmission components are designed and selected specifically for the high-speed, vibration environment of aero engines, exhibiting high reliability and long service life. Attached Figure Description

[0015] Figure 1 The diagram shown is a three-dimensional structural schematic of Embodiment 1 of the external casing-mounted detection device for the rotor speed of an aero-engine according to this utility model. Figure 2 The diagram shows a three-dimensional structure of the drive gear and transmission shaft in the external casing detection device for measuring the rotor speed of an aero-engine according to this utility model. Figure 3 The diagram shown is a three-dimensional structural schematic of Embodiment 2 of the external casing-mounted detection device for the rotor speed of an aero-engine according to this utility model. Figure 4 The diagram shown is a three-dimensional structural schematic of Embodiment 3 of the external casing-mounted detection device for the rotor speed of an aero-engine according to this utility model.

[0016] Explanation of reference numerals in the attached diagram: 1. Interface adapter; 2. Drive gear; 3. Transmission spindle; 4. Support bearing; 5. Bearing housing; 6. End cover; 7. Trigger gear; 8. Sensor bracket; 9. Sealing gasket; 10. Sealing structure. Detailed Implementation

[0017] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0018] Example 1 Please see Figures 1-2This utility model provides an embodiment: an external casing detection device for the rotor speed of an aero-engine, including an interface adapter 1 fixed to a spare interface on the engine casing, a drive gear 2 installed in the interface adapter 1 and meshing with the original gear inside the engine, a transmission main shaft 3 fixedly connected to the drive gear 2, a bearing housing 5 and an end cover 6 containing a pair of support bearings 4, the end cover 6 being located at the open end of the bearing housing 5, the support bearings 4 being used to support the transmission main shaft 3, and a trigger gear 7. The bearing housing 5 is fixedly connected to the interface adapter 1, the end of the transmission main shaft 3 extends out of the end cover 6, and the trigger gear 7 is installed at its end. A sensor bracket 8 for installing a sensor is provided on the bearing housing 5. The drive gear 2 and the transmission main shaft 3 are connected by a spline or interference fit. The support bearings 4 are paired angular contact ball bearings, and the trigger gear 7 is an involute gear or an equally spaced grooved disc structure.

[0019] During operation, the interface adapter 1 is fixed to the spare interface on the engine casing, providing a stable mounting base and a channel for communication with the engine interior. The drive gear 2 inside precisely meshes with the engine's existing gears, directly introducing the rotational power of the engine rotor into the device. The drive gear 2 transmits torque to the transmission spindle 3 via a high-rigidity spline or interference fit. This connection method ensures zero slippage and high efficiency in power transmission, avoiding speed measurement errors caused by loose connections. The transmission spindle 3 is supported by a pair of paired angular contact ball bearings within the bearing housing 5. These high-precision bearings not only withstand radial loads but also bidirectional axial loads, ensuring the spindle's stability, alignment, and minimal axial movement during high-speed operation, providing a foundation for accurate measurement. The bearing housing 5 provides precise mounting positioning and lubrication for the bearings. The space is enclosed at one end by the end cover 6, forming a complete support unit. The end of the transmission main shaft 3 extends from the center hole of the end cover 6, reliably exporting the rotational motion to the outside of the engine casing. At the end of the extended end of the transmission main shaft 3, a trigger gear 7 is installed. The trigger gear 7 rotates synchronously with the main shaft at high speed. According to the design, it can be an involute gear or an equally spaced grooved disc structure. The speed sensor, such as a magnetoelectric or eddy current sensor, fixed on the sensor bracket 8 is directly opposite the tooth edge or groove of the trigger gear 7. When the trigger gear 7 rotates, each tooth or groove passing through the sensor will cause a periodic change in the magnetic field or electric field of the sensor detection field. The sensor converts these periodic physical changes into a series of electronic pulse signals that strictly correspond to the engine rotor speed. By measuring the frequency of the pulse signal, the precise speed of the engine rotor can be calculated directly and in real time.

[0020] Example 2 Please see Figure 3The difference from Embodiment 1 is that a sealing gasket 9 is provided between the interface adapter 1 and the interface flange of the engine casing.

[0021] Adding a sealing gasket 9 between the interface adapter and the interface flange of the engine casing can effectively isolate the high-temperature, high-pressure oil and gas environment inside the engine from the outside world. Through the elastic compensation and media resistance of the sealing gasket 9, not only is lubricating oil leakage and contaminant intrusion prevented, but the long-term stability of the device under complex operating conditions is also improved. At the same time, this design reduces the risk of decreased measurement accuracy or component damage due to seal failure, and extends the service life of the device. It is particularly suitable for high-vibration and high-temperature aero-engine operating conditions, and takes into account both sealing reliability and ease of maintenance.

[0022] Example 3 Please see Figure 4 The difference from Embodiment 2 is that the end cap 6 is provided with a sealing structure 10, which is a lip seal or a labyrinth seal.

[0023] A lip seal or labyrinth seal is installed inside the end cover 6 to further enhance the dynamic sealing capability of the transmission spindle 3. The lip seal relies on its elastic lip to tightly fit the spindle, blocking the interaction between external impurities and internal lubrication media. The labyrinth seal forms airflow barrier through multi-stage meandering gaps, adapting to higher speed and temperature scenarios. This design significantly reduces measurement signal interference or bearing lubrication failure caused by seal wear, ensuring the continuity and accuracy of speed signal acquisition, while reducing maintenance frequency. It is especially suitable for the rotor speed monitoring needs of aero-engines that operate at high speeds for extended periods.

[0024] Through the above steps, by adopting a high-rigidity transmission shaft system and high-precision bearing support, the backlash and deformation in the transmission chain are significantly reduced, effectively eliminating deviations, drifts, and delays in the speed signal. It connects to the engine via a standardized interface adapter 1 and employs a professional end cap 6 sealing design, ensuring both installation alignment and accuracy while maintaining the original sealing performance of the engine casing. As an independent modular unit, it can be directly installed using the engine's existing spare interfaces without requiring structural modifications to the engine itself, making it particularly suitable for the modernization of older engines. All key transmission components are designed and selected specifically for the high-speed, vibration environment of aero engines, exhibiting high reliability and long service life. This addresses the problems of poor transmission chain rigidity and backlash in existing devices, which lead to signal deviations and delays; as well as insufficient sealing and reliability, which can easily cause leakage and wear under harsh operating conditions, threatening engine safety and increasing maintenance burden.

[0025] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. An external casing-mounted detection device for the rotor speed of an aero-engine, comprising an interface adapter (1) fixed to a spare interface on the engine casing, a drive gear (2) installed in the interface adapter (1) and meshing with an existing gear inside the engine, a transmission main shaft (3) fixedly connected to the drive gear (2), a bearing housing (5) containing a pair of support bearings (4), and an end cover (6), wherein the end cover (6) is located at the opening end of the bearing housing (5), and the support bearings (4) are used to support the transmission main shaft (3), characterized in that: It also includes a trigger gear (7), a bearing housing (5) and an interface adapter (1) are fixedly connected, the end of the transmission spindle (3) extends out of the end cover (6) and a trigger gear (7) is installed at its end, and a sensor bracket (8) for installing the sensor is provided on the bearing housing (5).

2. The casing-mounted detection device for measuring the rotor speed of an aero-engine according to claim 1, characterized in that: A sealing gasket (9) is provided between the interface adapter (1) and the interface flange of the engine casing.

3. The casing-mounted detection device for measuring the rotor speed of an aero-engine according to claim 1, characterized in that: The drive gear (2) is connected to the transmission spindle (3) by a spline or interference fit.

4. The casing-external detection device for measuring the rotor speed of an aero-engine according to claim 1, characterized in that: The support bearing (4) is a pair of angular contact ball bearings.

5. The casing-external detection device for measuring the rotor speed of an aero-engine according to claim 1, characterized in that: The end cap (6) has a sealing structure (10) inside.

6. The casing-external detection device for measuring the rotor speed of an aero-engine according to claim 5, characterized in that: The sealing structure (10) is a lip seal or a labyrinth seal.

7. The casing-external detection device for measuring the rotor speed of an aero-engine according to claim 1, characterized in that: The trigger gear (7) is an involute gear or an equally spaced slotted disc structure.

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