SU1578579A1 - Friction machine for investigating characteristics of triboconjugation in reciprocal movement - Google Patents

Abstract

The invention relates to test equipment, in particular to the structures of friction machines, which allow simulating the processes of alternating friction. The purpose of the invention is to increase the reliability of the test results by stabilizing the criteria of heat resistance, which is the product of the specific load on the slip rate. The loading unit is made in the form of a calibrated spring 9, a sleeve 10 with a roller 11, the axis of rotation of which is perpendicular to the axis of the sleeve 10. The sleeve 10 is designed to axially move along the holder 7 of the sample 8. A calibrated spring 9 is installed between the sleeve 10 and the holder 7 of the sample 8. The flat cam 12 is fixedly mounted on the holder 16 of the counter-sample 2. The cam 12 interacts with the roller 11. Because of the flat cam 12, the calibrated spring 9 receives additional compression, the law of variation of which is synchronized with the movement of the sample 8, which means with the speed of sliding. 4 il.

Description

31

The invention relates to testing equipment, in particular to the structures of friction machines, which allow to model the processes of alternating friction.

The aim of the invention is to increase the reliability of the test by stabilizing the criteria of heat resistance, which is the product of the specific load on the slip rate.

, Figure 1 shows a friction machine, a general view; figure 2 - section aa in Fig, 1; FIG. 3 is a graph showing the change in the criteria for heat resistance from the path of friction (for half the period of operation); in FIG. 4, the profile of the cam plane.

The friction machine contains a base 1, a mounted on it a contra-sample 2, a drive for its movement, made in the form of an electric motor 3, on whose shaft the crank 4 with a radius D / 2, a connecting rod 5 with a length of 1 and 6, a cylindrical holder 7 of sample 8, a node loading, made in the form of a calibrated spring 9 installed with the possibility of movement along the axis of the cylindrical holder 7 of sample 8 of the sleeve 10, the associated roller I1, the longitudinal axis of which is perpendicular to the longitudinal axis of the sleeve 10, and associated with the cam 2 2 mounted for movement relative to it and intended to interact with the roller 11. On the cylindrical holder 7 of the sample 8, an emphasis 13 is made, to which one end of the calibrated spring 9 is connected, the other end of which is connected to the sleeve 10. The roller 11 is connected by an axis 14 with a sleeve 10. The cylindrical holder 7 of sample 8 is mounted for movement in the guide 5. On the holder 16 of the counter piece 2, the stand 17 is rigidly fixed with grooves 18. The machine is equipped with a recorder or recording equipment (not yet ana) allowing locking guide tribological parameters such as such. as the temperature coefficient of friction, wear, etc.

The machine works as follows. When the electric motor 3 is turned on, the crank 4 begins to rotate, which, through the connecting rod 5 and 6, provides the reciprocating movement of the holder 16 of the counterpiece 2 from

0

five

0

five

0

five

0

with respect to the base I. For this, the holder 16 is designed as a dovetail guide.

The speed of movement of the counterpiece 2, fixedly fixed (clamps, screws, glue, soldering, etc.) on the holder 16, varies according to a complicated periodic law. To ensure the stability of the heat resistance criterion, a loading unit is provided that allows the specific pressure on the sample 8 to vary according to such a law that the heat resistance criterion, which is the product of the specific pressure P and slip velocity V, is constant over the greater part of the friction path PV - const.

Sample 8 is pressed against counterpiece 2 by a calibrated spring 9. During reciprocating movement of cam 12, sleeve 10 receives a vertical movement providing pressure variation on sample 8. For normal operation, there should be a joint between holder 7, sleeve 10 and guide 15 which provides only 1 axial vertical movement, but excludes rotation of these parts relative to each other. As such a joint, it is possible to use a spline or keyway sliding joint or to carry out a holder 7 with a non-circular cross section (ellipse, square, rhombus, etc.).

Different values of the PV criterion can be obtained by varying the load, for which movement of the cam 12 relative to the rack 17 in the slots 18 is provided. During the tests, the recording equipment records the main parameters of tribo-interaction.

PRI me R. Let us determine the profile of the flat cam 12 and the characteristics of the spring 9 for the friction machine, which ensures testing in the following modes:

Criterion of heat resistance, PVJ, kPa ,. m / s100 Contact area (working section of sample 2), A, mm2

100

Sliding speed range, V, m / s0-1 Parameters of the drive mechanism: Crank diameter, D, m 0.1

Connecting rod length

five

1m

0.2

Angular speed of the crank, with

20

The pressure in the pair sample-kontrabrets5 P F / A,

where F is the force of the spring;

A 100 mm, is the contact area. Connection between spring force F and slip speed V:

pV t V A

PV 100 kPa m / s

0.1

here

10 V

m mm

-

with

F

 Ipvj

01 100

H

The table shows the results of calculations.

For constructive reasons, we accept a spring having a hardness of C 1 N / mm, a wire diameter d of 1.2 mm, an initial length of 49 mm, the number of turns n 7. The force of the spring depends on its deformation

v - Y + h

Where b0 10 mm - deformation of the spring, corresponding to the minimum force F -10 N.

From here we find the y-coordinate of the cam profile corresponding to the deformation of the spring:

-Ј-ь

ABOUT

On the sections of the crank rotation of 15-30 °, and 150-165 °, which corresponds to 45 sample movement (0.021D-0.082D) and (О, 948D-0.987D) (dotted lines

five

ten

578579

4), the coordinate y is changed

very cool. This leads to jamming of the roller in the cams. Therefore, the working section of the cam profile must be in the range of 0.08 D to 0.95 D.

The use of a friction machine makes it possible to increase the reliability of the test results by stabilizing the PV criterion by 87% of the slide stroke. In addition, this friction machine makes it possible to experimentally determine the dependence of the main tribotechnical parameters of tribosprings on the heat resistance criterion in the case of reverse reciprocating interaction of the tribo interface.

15

0

five

0

five

0

five

Claims (1)

Invention Formula A friction machine for examining the characteristics of tribo-forces during reciprocating movement, comprising a base, a mounted counterbeat, a drive for moving it, a loading unit with a calibrated spring, a cylindrical sample holder associated with it, and a recorder that is different in order reliability, by stabilizing the heat resistance criterion, which is the product of the specific load on the slip velocity, the load unit is made as Moving along the axis of the cylindrical sample holder of the sleeve, a roller associated with it, the longitudinal axis of which is perpendicular to the longitudinal axis of the sleeve, and connected to the cam counterpiece, mounted for movement relative to it and interacting with the roller, on the cylindrical holder of the specimen there is a stop , which is connected to one end of the spring, the other end of which is connected to the sleeve. Moving the sample in fractions of diameter D 0.0210 0.0820 0.2970 0.5620 0.7970 0.9480 0.9870 3 4 1 РЦкПа-м.с1 100 OL08S w "We 1 Јf 100 mn 0.951 Sfx) Fig.Z