SU794439A1 - Instrument for determining friction coefficient - Google Patents

Description

FIG. 1 shows a general schematic diagram of the device; in fig. 2 - primary converter, section; in fig. 3 - General electrical circuit device.

The device consists of a traction element I, which is fixed on the drum 4 through the rollers 2 and 3. The rollers 2, 3 and the drum 4 constitute a transporting organ.

The drum 4 is mounted on an axis 5, which is driven in rotation through a gearbox 6 by an induction motor 7.

A primary transducer 8 is fixed on the traction element of the transporting body, having the ability to move along the surface of the container 9j into which the substance 10 is placed. At the ends of the container 9 there are limit switches //, 12.

The primary converter 8 is made inductive and consists of a body 13 with a coil 14 fixed in it, the latter has three windings; primary 15 and secondary 16, 17, which are counter-included. Counter connection of the secondary windings is necessary to compensate for the initial EMF in the absence of external load.

Inside the coil 14, a core 18 of magnetic material is moved, rigidly connected to a core 19 of non-magnetic material, deforming the spring 20.

A removable plate 21 is fastened to the bottom of the primary converter 8, which with its bracket 23 enters the groove 23 of the housing 13, and from the rear side of the housing 13 of the primary converter 8 is fixed by a screw 24 with a washer 25. The removable plate 21 is made of material to be tested .

On the upper part of the body 13 there is a finger 26 for fixing the weights 27.

The electrical circuit of the device consists (see Fig. 3) of a power supply unit 28, a frequency regulator 29, a power winding of an induction motor 7, a control unit 30 with a switch button 31, and also a measuring part including a stable current generator 32, which serves to power the windings 15, 16, 17 of the coil 14 of the primary converter 8 and the recording device 33.

The device works as follows. Beforehand, a removable plastic is attached to the primary converter 8. It is made of that material, the coefficient of friction with which matter 10 is: must be determined. On the container 9 with the substance 10 placed in it, install the primary converter 8 so that the removable plate 21 contacts the surface of the test substance 10.

The frequency of frequency adjuster 29 is set in accordance with the selected speed of movement of the primary converter.

When the start button 31 is pressed, the asynchronous motor 7, through the gearbox 6, rotates the axis 5 with the drum 4 mounted on it. The drum 4, the winding element 1, moves

the primary transducer 8 over the surface of the substance 10. At the same time, the friction forces arising between the removable plate 21 of the material under study and the substance 10 prevent the free movement

of the primary converter 8. As a result of the resulting force of friction, the rigidly connected cores 18, 19 are displaced relative to the coil 14, deforming the spring 20 by an amount proportional to

friction forces. The displacement of the core 18 of the magnetic material relative to the windings 15, 16, 17 of the coil 14 causes a change in the E.D.S. in the secondary windings 16, 17 of the coil 14 by an amount directly proportional to the deformation of the spring 20.

The change in emf is displayed and recorded by a recording device 33, the slit of which can be calibrated in direct physical terms.

When the primary converter 8 reaches the limit switch // the latter causes reversal of the asynchronous motor 7, which leads to

moving the primary converter 8 in the opposite direction. When the primary converter 8 reaches the limit switch 12, the motor is turned off, and the device returns to

initial position.

Thus, the device reliably, with great accuracy, measures and records the values of the coefficient of friction and the force of friction and does not require manual adjustment when the induction sensor is installed in the initial position.

The proposed device should be used not only to determine the coefficient of friction between a solid material and a plastic substance (product), but also between two solid materials or bodies.

Forgmula Invention

A device for determining the coefficient of friction predominantly between a substance and a solid material, containing a container for a substance, a removable plate made of the material under study, a transporting organ with a primary transducer fixed on it for measuring pulling force and an electric motor used to set in motion the transporting organ, that, in order to improve the determination accuracy, it is equipped with a frequency regulator, a current generator and a recording device, a removable plate from the The material is mounted on the primary converter, which is made inductive and connected to the current generator and the recording device, while the primary converter has a spring-loaded core connected to the transporting body.

Sources of information taken into account in the examination:

1. USSR author's certificate JMo 324556, cl. G 01 N 19/02, 1972.

2. Rogov M. A., Gorbatov A. V. New physical methods for processing m products. M., 1966, p. 88

 5 17

FIG. 2

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Fig.Z

Claims (1)

Claim A device for determining the coefficient of friction mainly between a substance and a solid material, containing a container for the substance, a removable plate of the test material, a transporting body with a primary transducer mounted thereon for measuring the pulling force, and an electric motor for driving the trans798439 porting body, characterized in that, in order to improve the accuracy of determination, it is equipped with a frequency controller, a current generator and a recording device, a removable plate from the studied Container material mounted on the primary converter, which is configured and connected to the induction generator and a current recording device, wherein the transducer is dammed nenny core associated with the transport body.