CN100478663C - Detector for measuring bearing friction torque - Google Patents

Abstract

The invention discloses a test device for measuring bearing friction torque, which comprises: an inner shaft, a casing, a force transmission pin, a cantilever beam, a stress and strain sensor, a strain collection and analysis instrument and a motor. When the motor drives the inner shaft to rotate, the inner ring of the tested bearing rotates with it. Due to the frictional torque between the inner and outer rings of the tested bearing, the torque signal of the inner and outer rings of the bearing is converted into the force of the power transmission pin. The signal is further converted into the strain signal of the cantilever beam, and then measured by the stress-strain sensor, the strain signal is converted into an electrical signal, and the electrical signal of the stress-strain sensor is converted and adjusted by the strain acquisition and analysis system, finally realizing the friction torque. High precision testing. The device provided by the invention avoids the disadvantages of traditional measuring devices such as low precision, low sampling frequency and display frequency, and inability to realize real-time measurement. It can also cooperate with low-speed and high-speed strain acquisition and analysis systems to obtain time-domain parameters and frequency spectrum characteristics, and comprehensively evaluate the performance of bearings.

Description

A kind of proving installation of measuring bearing frictional torque

Technical field

The present invention relates to the proving installation of bearing frictional torque, specifically be meant high precision, the real-time online testing device of space precise angular contact bearing its moment of friction under certain rotating speed, lubricated and preloaded condition.

Background technology

Moving component is widely used in finishing specific function in space satellite and the remote sensing instrument.Along with going deep into to the friction of spatial rotation mechanism, Study on Lubrication work, facts have proved of the further analysis of rail fault and research and a large amount of space and ground: bearing is the vital part of restriction spatial movement component life and reliability, to the test of bearing performance with estimate also and therefore become most important.Bearing frictional torque is one of important parameter of reflection bearing performance, especially the singularity that has of space applied environment lower bearing moment of friction, as microgravity: cause the lubricated fuel feeding mechanism in space with ground different, have only abutment surface tension force and capillary action under the weightlessness.High vacuum: cause lubricant volatilization to dissipate and localized hyperthermia of mechanism and cause lubricant failure.Temperature alternating: can directly influence the variation of lubricating oil viscosity.Cosmic dust: impact meeting direct, at a high speed brings very big interference to test.Space radiation: heat degeneration, chain rupture, polymerization and the cross-couplings etc. that cause lubricant.

At present, Chinese patent: all there is a common defective in the patent No. for the method for testing and the device of the bearing frictional torque that is provided such as 200610052086.8,200510049805.6,200410052708.8,03242670.4, promptly all do not relate to the lubrication state in the real work of bearing and preload condition, therefore can't obtain the andfrictional conditions in the bearing practical work process.Related platform such as vacuum sphere dish frictional testing machine and bearing assembly life test apparatus have been developed abroad, but be to solve specific problem according to the specific (special) requirements of project self mostly from engineering viewpoint, the correlation test data also belong to the engineering secret in a sense, are difficult in the article of publishing to find.Therefore, present needleless still is to the proving installation of the angular contact bearing moment of friction of space application.

Summary of the invention

Purpose of the present invention is exactly the proving installation that a kind of angular contact bearing moment of friction of using at the space will be provided.

Proving installation of the present invention comprises: by the groove body of interior axle 1 and shell 5 nesting measured bearings; The notch inboard have one be fixed on by screw 16 in gland bonnet 6 on the axle 1, be equipped with the pad 15 that bearing is applied preload between interior axle 1 and the gland bonnet 6; Have one to be fixed on gland 7 on the shell 5 in the notch outside, be equipped with the pad 15 that bearing is applied preload between shell 5 and the gland 7 by screw 16; Interior axle 1 adopts interference fit to connect with transmission shaft 8, and transmission shaft 8 connects with motor by shaft coupling 12; One end of semi-girder 10 has pin hole, and shell 5 bottoms have measured hole, and power transmission pin 9 cooperates connection with pin hole, measured hole respectively, is used for transmitted load; The other end of semi-girder 10 is fixed on the support 17 by screw 16, on semi-girder 10, is pasted with stress strain gauge 13 near support 17 places, and the signal of sensor output is handled by strain acquirement analytical instrument 14, realizes the test of bearing frictional torque.

When motor drives the transmission shaft rotation by shaft coupling, cooperate the inner ring of the interior axle drive measured bearing that connects to rotate with transmission shaft thereupon, because the effect of moment of friction between the inside and outside circle of measured bearing, the outer ring of measured bearing can have the trend of being draged because of the rotation of inner ring, moment is applied on the power transmission pin, the power transmission pin further is applied to the moment converting to force on the semi-girder again, semi-girder deforms under the effect of power load, convert power to strain, utilize the strain acquirement analytical instrument can realize high precision measurement bearing frictional torque.

Proving installation provided by the invention not only can on-line measurement shows the moment of friction of bearing under different rotating speeds, lubricated and preloaded condition in real time, can also cooperate low speed and high speed strain acquisition analysis system to obtain time domain parameter (mean value and waviness ratio) and spectrum signature, the performance of thoroughly evaluating bearing.

Description of drawings

Fig. 1 is the structural representation of bearing frictional torque proving installation of the present invention;

Wiring layout cuts open in the partial 3-D office of Fig. 2 bearing frictional torque proving installation of the present invention.

Embodiment

Below in conjunction with drawings and Examples the present invention is described in further detail:

The measured bearing 2 of present embodiment is two angular contact bearings that the DB mode connects, and bearing is embedded with ball 203 by outer ring 201, inner ring 202 and centre and constitutes.Inner ring between two bearings is separated by inner shield ring 3, and the outer ring between two bearings is separated by outer back-up ring 4.

During test measured bearing 2 is placed in the groove body that is made of interior axle 1 and shell 5, with screw 16 gland bonnet 6 is fixed on the interior axle 1, be equipped with the pad 15 that bearing is applied preload between interior axle 1 and the gland bonnet 6, the thickness of pad can determine according to the size that bearing is applied preload force, and make its inner ring that props up measured bearing 202.The inner ring 202 of measured bearing, inner shield ring 3 cooperate connection with interior axle 1, and the inner ring 202 of interior thus axle 1, measured bearing 2, inner shield ring 3 and gland bonnet 6 constitute an integral body and rotate with transmission shaft 8, are referred to as rotary part.

With screw 16 gland 7 is fixed on the shell 5, is equipped with the pad 15 that bearing is applied preload between shell 5 and the gland 7, the thickness of pad can determine according to the size that bearing is applied preload force, and make its outer ring that props up measured bearing 201.The outer ring 201 of measured bearing, outer back-up ring 4 cooperate connection with shell 5, and it is relative static that the outer ring 201 of shell 5, measured bearing, outer back-up ring 4 and gland 7 constitute an integral body maintenance thus, is referred to as stationary parts.

Adopt interference fit to link between transmission shaft 8 and the interior axle 1, motor 11 connects with transmission shaft 8 by shaft coupling 12, driven by motor transmission shaft 8 and rotary part rotate together, the moment of friction that shows as between rotary part, the stationary parts just of equal value of the moment of friction between the inside and outside circle of measured bearing this moment.

One end of semi-girder 10 has pin hole, and shell 5 bottoms have measured hole, and power transmission pin 9 cooperates connection with pin hole, measured hole respectively, is used for transmitted load; Power transmission pin 9 and semi-girder 10 can produce corresponding damping force to be stoped the motion of stationary parts and makes it to keep equilibrium state, realized that the moment of friction between the inside and outside circle of measured bearing is applied on the power transmission pin 9 with the form of power, and further be converted into the loading force on the semi-girder 10; Semi-girder 10 is out of shape under the effect of loading force, produces strain, has realized that loading force is converted into strain; Detect the strain that produces on the semi-girder 10 with the high precision stress strain gauge 13 that sticks on semi-girder 10 surfaces, realized that dependent variable is converted into electrical quantities; Electrical quantities with strain acquirement analytical instrument 14 counter stress strain transducers 10 transforms, nurses one's health, and has finally realized the high precision measurement of moment of friction.

Conversion formula between moment of friction M of the present invention and the strain stress is:

$M=\frac{E\&CenterDot;b\&CenterDot;{\mathrm{<figure-callout\; id="2"\; label="h"\; filenames="C20071004061200081.png"\; state="\{\{state\}\}">h</figure-callout>}}^2\&CenterDot;\mathrm{<figure-callout\; id="6"\; label="d"\; filenames="C20071004061200081.png,C20071004061200091.png"\; state="\{\{state\}\}">d</figure-callout>}}{6\&CenterDot;(L-x)}\&CenterDot;\mathrm{\&epsiv;}$

Wherein: E is the elastic modulus of semi-girder 10 materials, and L, b, h are respectively length, width and the thickness of semi-girder 10, d be power transmission pin 9 and the central shaft distance of transmission shaft 8, x is the paste position of sensor 13 is fixed on bracket end to semi-girder a distance.

The rigidity of the power transmission pin 9 in the proving installation of the present invention is not less than 200GPa, with the additional transmission error that reduces to cause because of 9 distortion of power transmission pin.The material of semi-girder 10 can be bronze, brass or stainless steel, and thickness is 1～2mm; If too thin then can cause its natural frequency low excessively, the vibration effect test result easily takes place, if too thick then can cause too small, the weak output signal of dependent variable, be difficult for detecting.Motor 11 can be direct current generator or stepper motor, can obtain required rotating speed by regulation voltage and dutycycle respectively.Sensor 13 can be resistance-type, condenser type, voltage-type equal stress strain transducer.

Strain acquirement analytical instrument 14 adopts low-speed device and high-speed equipment to combine:

Low-speed device can adopt commercially available static state or dynamic strain indicator (as the SDY2204 of the practical electronic technology Research Institute in Bei Dai River), realization is to the long-time detection of bearing frictional torque, result according to test can calculate its mean value and waviness ratio, as the time domain parameter of estimating the bearing working performance.

High-speed equipment can adopt the high speed data acquisition system (as the RBH8223H of Beijing Rui Bohua control technology company limited production) of commercially available built-in signal conversion and conditioning module, at first the signal of sensor is converted into voltage signal by wheatstone bridge circuits, carry out filtering then, amplify conditioning, sample afterwards, utilize fast fourier transformation algorithm that the result is carried out Fourier analysis at last, set up the spectrum signature of moment of friction and the corresponding relation of working condition.

Device provided by the invention can be changed different lubricants as required at any time to realize the purpose of contrast test, lubricant adopts fluid lubricant, behind rotary part and stationary parts adding lubricant, the design of hermetically-sealed construction can guarantee that lubricant can not leak in test process.

Claims (1)

1. A test device for measuring bearing friction torque, characterized in that the test device comprises: an inner shaft (1) and an outer shell (5) form a groove body for nesting a bearing to be tested; a screw (16 ) to fix the seal cover (6) on the inner shaft (1), between the inner shaft (1) and the seal cover (6) there is a gasket (15) for preloading the bearing; there is a screw passing through the outside of the slot (16) The gland (7) fixed on the shell (5), between the shell (5) and the gland (7), there is a gasket (15) for preloading the bearing; the inner shaft (1) and the transmission The shaft (8) is connected by interference fit, the transmission shaft (8) is connected with the motor (11) through the coupling (12); one end of the cantilever beam (10) has a pin hole, and the bottom of the housing (5) has a measuring hole , the power transmission pin (9) is connected with the pin hole and the measuring hole respectively to transmit the load; the other end of the cantilever beam (10) is fixed on the bracket (17) by a screw (16), and on the cantilever beam (10) A stress-strain sensor (13) is pasted near the bracket (17), and the signal output by the sensor is processed by the strain acquisition and analysis instrument (14), so as to realize the test of bearing friction torque.

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