CN100399003C

CN100399003C - Laser method for measuring vibration displacement of rolling bearing

Info

Publication number: CN100399003C
Application number: CNB2005100498041A
Authority: CN
Inventors: 张建忠; 汪久根
Original assignee: Zhejiang University ZJU
Current assignee: Zhejiang University ZJU
Priority date: 2005-05-24
Filing date: 2005-05-24
Publication date: 2008-07-02
Anticipated expiration: 2025-05-24
Also published as: CN1687720A

Abstract

The present invention discloses a laser measuring method of the vibration displacement of a roller bearing. A bearing to be measured is arranged on a rotating shaft of a test table, and laser reaches to the surface of a PSD sensor through the reflection of the surface of the bearing. A facula position is given by a PSD position sensor. An inner ring and a main shaft of the bearing can be regarded as a rigid body because an outer ring of the bearing receives the action of axial force. When the rotating shaft is rotated, the defects existing in the inner ring and the outer ring of the bearing, and a rolling body causes vibration. The position of the reflection laser on the PSD position sensor is used to reflect the vibration displacement s of any point on the surface of the bearing to be measured. The present invention has the advantages of simple mechanism, explicit principle and high precision, and the picking vibration effect is better than that of other type vibration tests. Besides, the influence on own vibration of a bearing system almost can be ignored. The laser measuring method has practicability and large economic development prospect for further improving the measuring accuracy and the application stability of bearing vibration, and the laser measuring method is suitable for the vibration measurement of any light reflecting surface, such as the vibration conditions of the surface of an automobile, etc.

Description

The laser measurement method of vibration displacement of rolling bearing

Technical field

The present invention relates to mechanical vibration and measure, be specifically related to a kind of laser measurement method of vibration displacement of rolling bearing.

Background technology

Bear vibration is measured generally two kinds of velocity profile and acceleration type measuring methods, and principle is respectively to measure sensing and piezoelectric crystal acceleration sensing with magnetic speed.In any case but, all need vibro-pickup to contact, and keep certain combination degree with bearing outside surface, also be certain rigidity, to improve the frequency response of system.The problem of its existence is: the vibro-pickup frequency response of mechanical type can not be too high, and the contact mounting means of sensor also causes the instability of measuring system.In order to improve the not high shortcoming of system frequency response, the magnetic-type mode that is installed of sensor had once appearred, but system complex, comparatively difficulty is used in dismounting inconvenience, but also needs to increase the process of demagnetization together.

Summary of the invention

For this reason, the object of the present invention is to provide the laser measurement method of touchless a kind of vibration displacement of rolling bearing, it has overcome deficiency of the prior art.

The technical solution used in the present invention is: measured bearing is installed in the rotating shaft of testing table, the laser that utilizes laser instrument to send arrives on the PSD position sensor surface through the measured bearing surface reflection, provide facula position by the PSD position transducer, because the effect of the suffered axial force in measured bearing outer ring, measured bearing inner ring and rotating shaft can be considered a rigid body, when rotating shaft is rotated, the defective that bearing inner race, outer ring and rolling body exist causes vibration, utilize the change in location of reflector laser on the PSD position transducer, reflect certain displacement s that a bit vibrates of measured bearing surface.

Adjust incident angle θ/2 and the PSD position transducer of laser instrument) incident angle pi/2-β, make laser to incident angle θ/2 on measured bearing surface in 15 °, accept in the measurement range that lasers range is in the PSD position transducer by adjust receiving the incident angle β of laser, making the PSD position sensor surface.

The displacement s of described vibration is:

With initial displacement is 0 point, s: the displacement of bearing measuring point, θ: twice laser incident angle, the incident angle of β: pi/2-β-PSD position transducer, the Displacement Measurement of S:PSD position transducer; Fetch bit moves the effective value of s as measuring judging quota after measuring.

The useful effect that the present invention has is:

1, avoiding wild effect in the contact chucking method, also is the rigidity instability of vibro-pickup; Being installed of heed contacted measure method is comparatively simple, easy to use, and precision guarantees easily, except common laboratory is measured, also can be applicable to the quality control and the online detection at Production of bearing scene;

2, make velocity survey and the mutual unified method of the acceleration analysis basis that measured bearing vibrates also to be displacement measurement; Displacement is carried out first difference and second order difference (perhaps differential can adopt mimic channel with raising speed) to the time, will obtain the velocity amplitude and the accekeration that vibrate respectively.

3, system frequency response can reach very high degree (more than the 2MHz), and measurement range almost can cover the vibration (under the rotating speed of bearing measuring standard code) of all frequencies of bearing.

4, measurement back fetch bit moves the effective value of s as measuring judging quota.

The present invention is not only applicable to the bear vibration industry, and is applicable to the detection of the vibration situation of any reflecting surface, as the vibration situation of engine or automotive surfaces.

Description of drawings

Fig. 1 is that laser method of the present invention is measured transverse bearing vibration synoptic diagram;

Fig. 2 is the calculating synoptic diagram of measuring in the bear vibration laser optical method of the present invention.

Among the figure: 1, laser instrument, 2, rotating shaft, 3, transverse bearing, 4, thrust device, 5, the PSD position transducer.

Embodiment

The invention will be further described below in conjunction with the drawings and specific embodiments.

Utilize the less characteristic of the angle of divergence of reflector laser, at terminal PSD position transducer, the micro-displacement in the measuring vibrations process settled of reflector laser.Will be bigger than the bearing measuring maximum frequency of oscillation far away owing to measure sample frequency, maximum frequency of oscillation is provided by measurement standard, so the result who measures can reflect the amplitude and the frequency status of bear vibration.

As Fig. 1, shown in Figure 2, the present invention is installed in measured bearing 3 in the rotating shaft 2 of testing table (holding the vibration survey testing table as the s0910 profile shaft), load from measured bearing 3 end faces by thrust device 4, make between the outer ring of tested transverse bearing 3 and rolling body and inner ring and the rolling body very close to each other, to embody the vibration situation that the bearing machining precision causes, the reflection that the laser that utilizes laser instrument 1 (as helium-neon laser) to send passes through measured bearing 3 surfaces arrives on the PSD position transducer 5, provide facula position by PSD position transducer 5, because the effect of the suffered axial force in measured bearing outer ring, measured bearing inner ring and rotating shaft 2 can be considered a rigid body, when rotating shaft 2 is rotated, the measured bearing inner ring, the defective that outer ring and rolling body exist causes vibration, utilize the change in location of reflector laser on PSD position transducer 5, reflect certain displacement s that a bit vibrates of measured bearing 3 surfaces.

Adjust incident angle θ/2 of laser instrument 1 and the incident angle pi/2-β of PSD position transducer 5, make laser to incident angle θ/2 on measured bearing surface in 15 °, accept in the measurement range that lasers range is in PSD position transducer 5 by adjust receiving the incident angle β of laser, making PSD position transducer 5 surfaces.

The displacement s of described vibration is:

As can be seen from Figure 1, this measuring method has realized the non-contact type pick-up, and the system responses frequency only depends on the response frequency of sensor and the processing speed of signal system.

As shown in Figure 2, when the position of measured bearing 2 changed, the surface location that the emission laser of laser instrument 1 is shone also can change to some extent, so that its incident angle needs is less as far as possible, can be similar to realization like this to certain any measurement.As shown in Figure 2, incident angle is θ/2, and reflector laser is pi/2-β to the incident angle of PSD position transducer light-sensitive surface, if precision is not enough, can adopt the way that reduces β to be improved.Displacement at the PSD sensor is under the situation of S, and the displacement s that can obtain measured bearing surface light spot is:

s＝S[cos(β-θ)+tg(β-θ)tg ^-1(θ)]

From above formula as can be seen, as long as in certain measurement range, promptly near the vibration situation on one point can access completely and unique determining.And can obtain the vibration situation of its speed and acceleration by its displacement.

Measure sample frequency and should surpass more than 8 times of highest frequency of vibration, formal use should can guarantee the stability of measurement data more than 20 times.Effective laser spot diameter on the PSD position transducer should be no more than 15% of PSD position transducer measurement range.

The present invention is not only applicable to bear vibration, is applicable to the measurement of surperficial microvibration situation simultaneously, as the vibration situation of engine or automotive surfaces yet.

Above-mentioned embodiment is used for the present invention that explains, rather than limits the invention, and in the protection domain of spirit of the present utility model and claim, any modification and change to the present invention makes all fall into protection scope of the present invention.

Claims

1. the laser measurement method of a vibration displacement of rolling bearing, it is characterized in that: measured bearing (3) is installed in the rotating shaft (2) of testing table, the laser that utilizes laser instrument (1) to send arrives on PSD position transducer (5) surface through measured bearing (3) surface reflection, provide facula position by PSD position transducer (5), because the effect of the suffered axial force in measured bearing outer ring, measured bearing inner ring and rotating shaft (2) can be considered a rigid body, when rotating shaft (2) is rotated, bearing inner race, the defective that outer ring and rolling body exist causes vibration, utilize the change in location of reflector laser on PSD position transducer (5), reflect certain displacement s that a bit vibrates of measured bearing (3) surface; Adjust incident angle θ/2 of laser instrument (1) and the incident angle pi/2-β of PSD position transducer (5), make laser to incident angle θ/2 on measured bearing surface in 15 °, accept in the measurement range that lasers range is in PSD position transducer (5) by adjust receiving the incident angle β of laser, making PSD position transducer (5) surface.

2. the laser measurement method of a kind of vibration displacement of rolling bearing according to claim 1, it is characterized in that: the displacement s of described vibration is: