Helicopter tail transmission shaft torque measuring device

Abstract

The utility model belongs to the technical field of helicopter ground comprehensive test, and relates to a helicopter tail transmission shaft torque measuring device, which comprises an acquisition module, an induction coil, a receiver and a decoder, the acquisition module is attached to the surface of the tail transmission shaft for installation and fixation, an induction coil is wound on the tail transmission shaft, and the acquisition module is connected with the induction coil; the receiver is arranged beside the tail transmission shaft and is opposite to the induction coil, and the receiver is connected with the decoder; the receiver and the induction coil transmit electric energy and data in an electromagnetic induction mode. The acquisition module is used for acquiring a torque signal and performing PCM coding, and the torque signal is received by the induction coil and the receiver and then decoded by the decoder.

Description

TECHNICAL FIELD

[0001] The utility model belongs to helicopter ground comprehensive test testing technical field relates to a kind of helicopter tail transmission shaft torque measuring device. BACKGROUND

[0002] Helicopter transmission shaft system is elastomer, with rich torsional vibration, under certain conditions, helicopter power transmission chain torsional vibration and fuel control device, control law will form self-excited oscillation system, in fuel control system, recess filter is inserted into to prevent the effective measure of this coupled oscillation.For this, need to obtain torsional vibration low-order natural frequency by torsional vibration frequency test to correct the center frequency of recess filter, then verify the stability of transmission chain torsional vibration and engine fuel control system coupling by torsional vibration stability test.In torsional vibration frequency and torsional vibration stability test, it is usually through measuring rotor shaft, engine power output shaft torque signal to analyze torsional vibration frequency, but due to the torsional stiffness of rotor shaft and engine power output shaft is large, it is not easy to ensure the accuracy of torsional vibration frequency measurement, therefore, it is urgent to measure tail transmission shaft torque to directly reflect the torsional vibration of transmission system Fluctuation, improve torsional vibration frequency measurement accuracy.

[0003] Tail transmission shaft is test piece, test cannot change its installation state and surface finish properties, test device installation space is extremely limited, and tail transmission shaft is high-speed rotating thin-walled hollow piece, and dynamic balance requirement is also extremely high.Therefore, a kind of weight is required, which has little effect on tail transmission shaft dynamic balance, and measures in the case where tail transmission shaft installation state and appearance are not changed. UTILITY MODEL CONTENTS

[0004] Utility model purpose: propose a kind of helicopter tail transmission shaft torque measuring device, which has little effect on tail transmission shaft dynamic balance, and does not change tail transmission shaft installation state and appearance.

[0005] Technical scheme

[0006] A kind of helicopter tail transmission shaft torque measuring device, it include: acquisition module, inductive coil, receiver and decoder;

[0007] Acquisition module is attached to the surface of tail transmission shaft and is fixed, inductive coil is wound on tail transmission shaft, and acquisition module is connected with inductive coil;

[0008] Receiver is arranged at the side of tail transmission shaft and is oppositely arranged with inductive coil, and receiver is connected with decoder;

[0009] Receiver and inductive coil transmit electric energy and data by the way of electromagnetic induction;

[0010] Acquisition module is used for collecting torque signal and carrying out PCM encoding, after being received by inductive coil and receiver, it is decoded by decoder.

[0011] Further, the acquisition module collects torque through the strain gauge sensor, and a non-elastic adhesive tape with tensile strength not less than 100 kg / 25 mm is wound around the tail transmission shaft for fixation.

[0012] Further, two layers of ferrite tapes are wound around the surface of the tail transmission shaft, and enamel wires are wound around the surface of the tapes to form coils; the coils include data coils and power coils; the power coils are used for power supply of the acquisition module, and the data coils are used for transmission of data collected by the acquisition module.

[0013] Further, the distance between the receiver and the coils ranges from 15 mm to 25 mm.

[0014] Further, the receiver emits strong magnetic radiation to the coils for power supply, and receives torque data transmitted by the coils through electromagnetic induction.

[0015] Further, the receiver is a cuboid with an output cable, and emits strong magnetic radiation at 30-60 kHz.

[0016] In summary, the beneficial effects of the utility model are as follows:

[0017] 1) The signals detected on the rotating shaft can be reliably and extremely simply transmitted to the ground data acquisition system;

[0018] 2) The measurement circuit on the tail transmission shaft is powered by induction, which greatly reduces the weight of the acquisition module on the tail transmission shaft compared with most battery-powered systems, and is more conducive to the dynamic balance of the tail transmission shaft which is a high-speed, thin-walled, lightweight shaft;

[0019] 3) The installation state of the tail transmission shaft has no any influence, and the shaft surface is not damaged, the installation and disassembly are convenient, and the important components can be reused;

[0020] 4) The energy consumption is low, the test time is not limited by the battery capacity and life, the efficiency is improved, and the maintenance time is also reduced;

[0021] 5) The diameter range of the measurable shaft is wide (20-1000 mm), the signals below 5000 με can be collected, it is suitable for use in a scene below 2600 rpm, the operation is convenient, there is no mechanical movable part in the acquisition module, the influence of vibration is small, the long-term stability is high, and the test precision is high. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 It is a schematic view of a helicopter tail transmission shaft torque measuring device. DETAILED DESCRIPTION

[0023] A helicopter tail transmission shaft torque measuring device, mainly composed of acquisition module, induction coil, receiver and decoder. The torque signal on the rotating shaft is amplified, filtered and transmitted to the ground by wireless transmission, and finally processed, analyzed and displayed in the ground data acquisition system. The working process is: the torque signal is introduced to the transmitting module through the strain gauge, the transmitting module outputs the pulse code modulation signal (PCM code stream) to the induction coil on the shaft, the magnetic field of the coil enables the signal to be inductively transmitted to the receiver, the receiver is transmitted to the decoder through the cable, the digital signal is converted to analog signal, and finally enters the ground data acquisition system, realizes the real-time accurate measurement of dynamic torque signal. The power supply of the acquisition module is realized by induction.

[0024] The specific installation method and working form of the device are:

[0025] 1) Acquisition module: install the acquisition module close to the rotating shaft, use non-elastic tape (glass fiber tape) with high tensile strength (100 kg / 25 mm) to wrap it with the shaft, and fix it. According to the speed and diameter of the shaft, soft tube clamp can be used to finally fix the acquisition module to ensure the safe installation of the assembly. The acquisition module is responsible for A / D acquisition of the torque signal of the shaft and PCM encoding;

[0026] 2) Induction coil: wrap two layers of special ferrite tape on the rotating shaft on the side of the acquisition module, separate each layer with glass fiber tape to isolate the magnetic field between the shaft and the coil. Wrap 0.5mm enameled wire outside the magnetic tape to make the coil. The main influencing factors of the number of turns of the coil are the diameter, material and surrounding environment of the shaft. Generally between 5-18 turns, one more or one less can be tried to optimize the results. Remove the insulating layer at the end of the enameled wire and weld the wire of the coil to the input pin. Wrap a special fiber-reinforced tape outside the coil. Power the acquisition module through the enameled wire in an inductive power supply mode, and transmit the acquired torque signal to the receiver in an inductive coupling mode;

[0027] 3) Receiver: the receiver is a 66*33*53mm cuboid with an output cable. It emits strong magnetic radiation at 30-60kHz, with a distance of 20cm, and is connected to the bracket on the bearing seat through two self-made through holes. The distance between the receiver and the coil needs to consider the shaft rotation jump displacement and the shaft dynamic deformation of the receiver installation position. Generally about 15-25mm, the actual can be evaluated according to the previous test experience whether it is within the safe distance of the measured shaft movement.

[0028] 4) Decoder: The decoder is fixed on the non-rotating frame of the rotating shaft accessory, and is connected with the receiver through a cable. The signal received by the receiver is converted into an analog signal after entering the decoder, and finally enters the ground data acquisition system. The decoder outputs power supply for the receiver, and the system can directly set the gain and automatic zero from the decoder.

[0029] 1) Design of micro acquisition module and application of inductive power supply: The size of the acquisition module of the system is 35*18*12mm, and the weight is 13g. The inductive power supply is used to supply power to the measurement circuit on the tail drive shaft, which greatly simplifies the weight of the shaft test system. It is convenient to carry and install, and has little effect on the dynamic balance of the shaft system, especially suitable for measuring the torque of the shaft with high speed, small diameter and limited installation space. In addition, the service life of the inductive coil is long, and the maintenance cost is low;

[0030] 2) Application of non-invasive non-contact measurement: The acquisition module of the torque measurement device is light in weight, and the test modification is simple and feasible. It does not need to make any changes to the installation state of the measured shaft, and does not damage the surface of the shaft, so it can be reliably installed;

[0031] 3) Application of pulse code modulation signal: The transmission module outputs pulse code modulation signal, that is, PCM code stream, and the test data is transmitted through digital signal, so the signal-to-noise ratio is greatly improved, and the test precision can reach 0.2%;

[0032] The connection mode of each important component of the system is shown in Figure 1 The mass distribution of the rotating part is: the acquisition module is 13g, the inductive coil is 8g, and the installation tape, glue and other materials are about 100g. The axial length of the rotating part after installation is about 140mm, and the radial thickness is about 10mm.

Claims

1. A helicopter tailshaft torque measuring device, characterized by: The device comprises: a collection module, an induction coil, a receiver and a decoder; the collection module is fixedly attached to the surface of the tail drive shaft, the induction coil is wound around the tail drive shaft, and the collection module is connected to the induction coil; a fiber-reinforced belt is wound around the outside of the coil; the receiver is arranged beside the tail drive shaft and opposite the induction coil, and is connected to the decoder; the receiver and the induction coil transmit electric energy and data through electromagnetic induction; the collection module is used to collect torque signals and perform PCM encoding, and the signals are received by the induction coil and the receiver and then decoded by the decoder; the collection module collects torque through a strain gauge sensor, and is fixedly wound around the tail drive shaft by using a non-elastic adhesive tape with a tensile strength not less than 100 kg / 25 mm; according to the rotational speed and diameter of the shaft, a hose clamp is additionally used to finally fix the collection module, so as to ensure the safe installation of the assembly.

2. The apparatus of claim 1, wherein: Two layers of ferrite tapes are wound around the surface of the tail drive shaft, and the surface of the tapes is wound with enameled wire to make a coil; the coil comprises a data coil and a power coil; the power coil is used to supply power to the collection module, and the data coil is used to transmit the data collected by the collection module.

3. The apparatus of claim 2, wherein: The distance between the receiver and the coil is within the range of 15 mm to 25 mm.

4. The apparatus of claim 3, wherein: The receiver emits strong magnetic radiation to the coil for power supply, and receives the torque data transmitted by the coil through electromagnetic induction.

5. The apparatus of claim 4, wherein: The receiver is a cuboid with an output cable, with a size of 66*33*53 mm, and emits strong magnetic radiation at a frequency of 30-60 kHz.

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