CN2103816U

CN2103816U - Vibration tachometer

Info

Publication number: CN2103816U
Application number: CN 91215837
Authority: CN
Inventors: 钱网生
Original assignee: No704 Inst Of No7 Academy Of China Shipbuilding Corp
Current assignee: No704 Inst Of No7 Academy Of China Shipbuilding Corp
Priority date: 1991-08-27
Filing date: 1991-08-27
Publication date: 1992-05-06

Abstract

The utility model provides an improved novel tachometer. The utility model makes use of a rotating machine having the characteristic that a rotation centrifugal force generates vibration and uses a vibration sensor to obtain a signal, the rotation speed value is obtained on a rotation speed digital display through an amplifying circuit, a filter circuit, a frequency selecting circuit and a counting circuit, and the utility model also uses the vibration sensor to obtain a vibration measuring value on a vibration-grade display meter through a root mean square detection circuit. The improved tachometer is particularly suitable for measuring the rotation speed of a machine with a fully closed rotating shaft which is not exposed, a tachometer on the present market has no such function, and the utility model can also be used for measuring vibration, having the characteristic of multifunction.

Description

Vibration tachometer

The utility model relates to a kind of improved rotational speed meters, particularly a kind of oscillatory type rotational speed meters.

The rotational speed meters of the measurement the taken machine rotational speed that provides on the market has electric revolution indicator, coil induction type digital tachometer, infrared ray tachometer gage, contact type tachometer gage or the like now, and these instrument can only be measured visible and come-at-able rotating shaft rotating speed.In order to measure totally enclosed rotating shaft rotating speed is to adopt mechanical resonance reed rotational speed meters, it is made up of the reed of tens different qualities, each reed has a natural frequency, when this rotational speed meters is directly installed on the selected position of machine, the vibration frequency that machine run produced is when the frequency of a certain reed is identical in the vibrating sheet rotational speed meters together, just produce resonance, i.e. the vibration displacement maximum of Chan Shenging, the gauger measures the rotating speed of this rotating shaft in view of the above.Mechanical resonance reed rotational speed meters, owing to be subjected to the restriction of reed number, measuring accuracy is lower, measurement range is less; Rotational speed meters must directly be contained on the measured machine, the instrument sensitive for damages; Reed quantity is many, complex structure, poor reliability.

Task of the present utility model is that axle rotating speed that totally-enclosed machine of a kind of energy measurement or rotating shaft do not expose, measuring accuracy height, range is big, reliability is high rotational speed meters will be provided.

The rotation that task of the present utility model is achieved in that machine is part or parts in addition, because foozle and material is inhomogeneous, can produce centrifugal force when rotatablely moving, and the vibration that centrifugal force produces is simple harmonic oscillation, its vibration frequency is consistent with the rotating speed of axle, utilize this principle, with vibration transducer (accelerometer or velograph), the vibrative position of surface energy reflection rotary centrifugal force from machine, gather the vibration signal of machine, and this conversion of signals become electric signal, pass through the low-noise charge pre-amplification circuit of connection then, bandwidth-limited circuit, frequency selective network and counting circuit finally provide the tachometer value of measuring machine on the rotating speed digital indicator of panel.When connect root mean square detecting circuit and vibration level display gauge head after pre-amplification circuit, the oscillatory type rotational speed meters can possess the function of measuring machine vibration again, and its vibration survey not only is suitable for rotating machinery, and is applicable to the vibration of all machines.

The utility model adopts sensor to gather vibration signal at machine surface, instrument itself is not influenced by machine vibration, both the totally-enclosed machine of energy measurement the axle rotating speed, can improve the reliability of instrument work again, its circuit design does not have the obstacle of physical construction, can guarantee that instrument has higher measuring accuracy, measurement range is also big.The utility model can not only be measured machine rotational speed, and the energy measurement machine vibration, makes the multi-functional feature of instrument tool.

Concrete structure of the present utility model is provided by following embodiment and accompanying drawing thereof.

Fig. 1 is the arrangenent diagram of overlooking that a kind of concrete structure of the utility model takes off top board.

Fig. 2 is the arrangenent diagram of facing that Fig. 1 takes off panel.

Fig. 3 is the utility model theory diagram.

Fig. 4 is Fig. 1 panel arrangement synoptic diagram.

Fig. 1,2 shows, voltage-stabilized power supply circuit and circuit board 1, band pass filter circuit and circuit board 2, Frequency Band Selection circuit and circuit board 3, counting circuit and circuit board 4, electric charge pre-amplification circuit and circuit board 5, panel 6, casing 7, cable 8, sensor 9, root mean square detecting circuit and circuit board 10.Fig. 4 shows vibration performance selector switch 11, range switch 12, vibration level display gauge head 13, rotating speed digital indicator 14, rotating speed selection pilot lamp 15, rotating speed selector switch 16, counting selector switch averaging time 17, power switch device 18, vibration transducer input 19, upper limiting frequency selector switch 20, gauge outfit displayed value selector switch 21, vibration signal switch averaging time 22.

With reference to Fig. 1,2, voltage-stabilized power supply circuit 1, band pass filter circuit 2, Frequency Band Selection circuit 3, counting circuit 4 and electric charge pre-amplification circuit 5 all are located on the corresponding circuit board, these circuit boards are installed in the casing 7 again, the dead ahead installing panel 6 of casing 7, vibration transducer 9 can be taken accelerometer or velograph usually, and sensor 9 connects with cable 8 and the casing 7 inner electric charge pre-amplification circuits of installing 5.With reference to Fig. 3,4, when using, vibration transducer 9 selects the suitable arrangement point, to obtain the fundamental vibration signal relevant with shaft vibration, and convert vibration signal to electric signal, this signal obtains the reading of machine rotational speed at last successively by electric charge pre-amplification circuit 5, bandwidth-limited circuit 2, Frequency Band Selection circuit 3 and counting circuit 4 on the rotating speed digital indicator 14 on the panel 6.When instrument uses,, can gather machine whirling vibration and can work, thereby machine is totally enclosed that rotating shaft does not expose cannot see condition such as also can't contact, and all can utilize the utility model to measure as long as sensor is placed into the appropriate location of machine.In addition, during instrument work, have only sensor to contact with machine, instrument itself can be placed on the good horizontal face, thereby can not be subjected to the infringement of machine vibration, its functional reliability height; Instrument is made up of various circuit, not as the mechanical measurement element of classes such as reed, thereby guarantees that instrument has higher measuring accuracy and bigger measurement range.When appliance requires adds the measuring vibrations function, use same sensor 9, by root mean square detecting circuit 10, on the vibration level display gauge head 13 on the panel 6, obtain survey measurements.Both can measure the vibration of rotating machinery, also can measure the vibration of non-rotating machinery, and make instrument have multi-functional feature.

Claims

1, one by voltage-stabilized power supply circuit 1, band pass filter circuit 2, Frequency Band Selection circuit 3, counting circuit 4, electric charge pre-amplification circuit 5, panel 6, casing 7, cable 8, the oscillatory type rotational speed meters that sensor 9 is formed, the sensor 9 that it is characterized in that instrument is vibration transducer, sensor 9 is connected in low-noise charge pre-amplification circuit 5 through cable 8, circuit 5 is connected in bandwidth-limited circuit 2, circuit 2 is connected in frequency selective network 3, circuit 3 is connected in counting circuit 4, circuit 4 is connected in the rotating speed digital indicator on the panel 6, another road is that circuit 5 is connected in root mean square detecting circuit 10, and this circuit 10 is connected in the vibration level display gauge head again.

2, tachometer gage according to claim 1 is characterized in that vibration transducer 9 is accelerometers, also the available velocity meter.