SU1663507A1 - Method and apparatus for friction and wear testing of materials - Google Patents

Abstract

This invention relates to friction testing of materials. The purpose of the invention is to improve the economy by more rational use of the counter-sample. This is achieved by creating a variable frequency N of rotation of the counterpiece, defined by the formula N = V / 2ϕD, where V is the speed of movement of the sample along the counterpiece, and D is the transverse size of the sample along the counterpiece sample radius. The device contains sample 2, mounted in holder 1 with guides 3, disk counterpiece 5, mounted in holder 4, mechanism 6, drum 7 with cable 8 to move sample 2, unit for changing frequency of rotation of counterparticle 5, including pulley 13c. 14, connected with a profiled drum 11 by a V-belt 12 and located on the same shaft 15 with a counter piece, an actuator 9 located on the same shaft 10 with the drums 7 and 11. 2 sec. f-ly, 2 ill.

Description

The invention relates to the testing of materials by friction and can be used to study the tribotechnical properties of materials of friction units operating under complex laws of changing the load and speed modes of friction under conditions of dry or boundary lubrication.

The purpose of the invention is to increase efficiency by more rational use of the surface of the counter piece.

FIG. 1 shows a diagram of an apparatus for carrying out the method; in fig. 2 shows the relationship of the tangent oiR counter-sampling rate and speed

the sample displacement is -t- with the required law of variation of the relative sliding velocity V (t).

The device contains a holder 1 of sample 2 material, which is installed in guides 3, a holder 4 of a disk counter sample 5, a mechanism 6 for pressing a sample against a counter sample, a mechanism for radial movement of sample 2 relative to counter sample 5, made in the form of a drum 7 with a variable radius along its axis and a screw groove on the side surface and located in the groove of the cable 8, fixed by the free end on the holder 1 of sample 2, the rotational drive 9, the shaft 10 of which is connected to the drum 7. An additional bar is mounted on the same shaft 10 aban 11 with a variable radius along its axis, which is connected with a pulley 13 by means of a wedge belt 12, which in turn has guides

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ON SLED SL

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14. In this case, the pulley 13 is located on a common shaft 15 with the holder 4 of the counter piece 5.

The method with this device is carried out as follows.

Sample 2 of the material under investigation is installed, supported in holder 1, anywhere on the disk counter piece 5 located in holder 4. Mechanism 6 creates the required compressive force. The drive 9 and thus the reels 7 and 11 are driven into rotation. A cable 8 is wound on the drum 7, moving sample 2 along the surface of the counter sample 5. At the same time, the drum 11 drives the pulley 13 and the shaft 15 through rotation 15 of the counter edge. the pulley 13 allows it to move along the shaft 15 following the movement of the belt 12 along the drum 11 without mutual rotation of the pulley 13 and the shaft 15. The drum profile is selected on the basis of the required law of variation of the speed V of sample slip along the counterpiece.

In order to ensure a given law of variation of the relative slip velocity V when testing over the untreated surface of the counterpiece with the maximum efficiency of its use, the law of change in the frequency and rotation of the counterpiece is chosen according to the formula (see Fig. 2).

, 2

(D

At one turn in this case, the sample moves radially to a distance equal to its transverse size R

 M2)

Substituting the expression (2) in (1), get

(cod) 2 + 0 V2; (2l nd) 2 V2;

-et- (3

At the same time, the sample draws on a disk counter-rim a helix-type Archimedes helix with a distance between the turns equal to the transverse size of the sample, moving at any time on the non-worked surface with the required laws of the velocity change ().

compression and specimen compressive strength, so that the central part of the sample passes the sample more slowly, which leads to a more complete, maximum use of the surface of the contra-sample friction.

Claims (2)

Claim 1. Method of testing materials for friction and wear, which consists in pressing a sample of a material with a constant load to the empty surface of a disc counterpiece, rotate the counter sample and at the same time report forward movement of the sample with a variable speed V along the radius of the disk counter edge and determine the tribological parameters, characterized in that, in order to improve efficiency by more rational use of the surface of the counterpiece, rotation of the counterpiece is tvl dissolved variable frequency f, which is selected from conditions 25 P V 2nd where d is the transverse size of the sample along the radius of the counter piece. 2. A device for testing materials for friction and wear, containing holders of a disk counter sample and a material sample, a mechanism for pressing a sample against a counter sample, a mechanism for radial movement of a sample relative to a counter sample, made in the form of a drum with a variable radius along its axis and a helical groove on the lateral surface and located in the groove of the cable attached to the free end on the holder the sample and the rotational drive, the shaft of which is associated with the drum and with the disk counterpiece holder. characterized in that the connection of the rotational drive shaft with the disk counterpiece holder is made in the form of an additional drum mounted on the drive shaft with a variable radius along its axis, a pulley with guides located on a common shaft with a counterpiece holder, and V-belt covering the pulley and an additional drum. J / f / j / Ya77G t 4Јsc / mmmvmvm / J777