RU199337U1 - FRICTION MACHINE - Google Patents

Abstract

The utility model relates to the field of testing equipment, namely, friction machines for testing and rapid assessment of lubricating and antifriction properties of oils, greases and lubricants. The friction machine contains a body 1, inside which a tray 2 is installed for the tested lubricant. A hinged loading lever 3 is also installed in the body, on which a force-measuring device 4 (electronic steelyard) is installed. The suspension of the force-measuring device 4 is connected to the spring 5 of the loading mechanism, which is a screw pair: a screw 6, driven in rotation by a handle 9, with a nut 7, combined with a slide 8. A sample 11 is fixed on the lever 3 in the holder 10. Counter-sample 12, intended for immersion in the tested lubricant, which fills the bath 2, is rigidly mounted on the first half shaft 13. The counter sample 12 is connected to the engine 14 through the torque limit clutch 15 and the first belt drive 16, the pulley 17 of which is installed on the second half shaft 18. The engine 14 is connected to the speed governor 19, which is an integral element of the control system 20 with feedback from the tachogenerator 21, which is connected through the second belt drive 22 with the pulley 23 fixed to the first half shaft 13. The control system 20 also includes: a shutdown unit 24 with a relay 25, a power supply 26 and buttons "Start" and "Stop" 27. Elements of the control system 20 are located in the housing 1 and are connected The achieved technical result is an increase in the accuracy and reliability of the results of testing lubricants by ensuring stable repeatability of the experimental conditions. 1 ill.

Description

The utility model relates to the field of testing equipment, namely, friction machines for testing and rapid assessment of lubricating and antifriction properties of oils, greases and lubricants.

Known Universal machine for testing friction and wear II-5018, [Kombalov B.C. Methods and means of testing for friction and wear of structural and lubricating materials: handbook / ed. K.V. Frolova, E.A. Marchenko. - M .: Mechanical Engineering, 2008. Pp. 97.], which includes a frame, an electric drive, a loading device and a measuring panel. The loading device is made in the form of a spring, an earring and a folding headstock.

The main disadvantages of this friction machine are:

- large dimensions and weight, which determines their only stationary use; the test duration is long enough to obtain test results for lubricants.

The prototype of the proposed utility model is a device for testing oils at friction [Patent for utility model RU 104722 U1. publ. 05/20/2011], containing a base, a load arm pivotally mounted on it, a sample mounted in a holder on the lever, made in the form of a rolling bearing roller, and a counter-sample in the form of a rolling bearing ring placed in the holder on the base. The measuring mechanism is made in the form of a faceted pin mounted on the sample holder, interacting with a torque wrench, and an ammeter connected to the engine.

This prototype has several disadvantages:

- manual application of the load cannot ensure the uniformity and constancy of the applied load;

- a change in the load on the samples, leads to a change in the speed of rotation of the engine, which constantly changes the friction conditions during testing (there is no steady mode of friction of the samples)

- measurement of the motor current is a poorly accurate method for determining the load torque (the motor current, when operating under load, depends on a large number of factors that are difficult or impossible to assess quickly).

The objective of the claimed utility model is to reduce the impact of these shortcomings on the test results. The achieved technical result is an increase in the accuracy and reliability of the results of testing lubricants by ensuring stable repeatability of the experimental conditions.

The problem is solved by the fact that the friction machine contains a housing with a loading lever hinged in it, on which a holder with a sample installed in it is fixed. The friction machine also contains a counter-sample, kinematically connected to the engine, a loading mechanism, a force-measuring device mounted on the loading arm and a control system. It differs from the prototype in that the loading mechanism is a screw pair that includes a screw connected to the rotation handle and a nut that is aligned with a slide connected to a spring that is connected to the suspension of the force-measuring device. The counter-sample is installed on the first half-shaft and is connected to the engine through the torque limit clutch and the first belt drive, the pulley of which is installed on the second half-shaft. In this case, the engine is connected to a speed controller, which is connected to the first half-shaft through a tachogenerator and a second belt drive. The control system also includes a power supply connected to the shutdown unit, a relay, and start and stop buttons.

It is preferable to use an electronic balance wheel as a force-measuring device.

In order to better demonstrate the distinctive features of the utility model by way of example, without any limiting character, a preferred embodiment is described below. An example of implementation is illustrated by the Figure, which shows a general layout diagram of a friction machine.

The friction machine contains a housing 1, inside which a tray 2 is installed for filling with the tested lubricant. A hinged loading lever 3 is also installed in the housing, on which a force-measuring device 4 is installed on the opposite side of the hinge. It is preferable to use an electronic balance wheel as a force-measuring device. The suspension of the force-measuring device 4 is connected to the spring 5 of the loading mechanism, which is also installed inside the housing 1. The loading mechanism is a screw pair: screw 6 with nut 7, which is aligned with the slide 8. The screw 6 of the loading mechanism is rotated by the handle 9. On the lever 3 a sample 11 is fixedly fixed in the holder 10. The counter sample 12 (intended for immersion in the tested lubricant, with which the tank 2 is filled), is rigidly mounted on the first half shaft 13. The counter sample 12 is connected to the motor 14 through the clutch 15 of the limit moment and the first belt drive 16, the pulley 17 of which is installed on the second half-shaft 18. Engine 14 is connected to a speed regulator 19, which is an integral element of the control system 20 with feedback from the tachogenerator 21, which is connected through a second belt drive 22 with a pulley 23 attached to the first half-shaft 13. Control system 20 also includes: shutdown block 24 with relay 25, block power 26 and buttons "Start" and "Stop" 27. Elements of the control system 20 are located in the housing 1 and are connected to it.

The friction machine works as follows:

The lever 3 is lifted up on the hinge, the sample 11 is placed in the holder 10. The bath 2 is filled with the tested lubricant and installed in the housing 1 so that the counter sample 12 is immersed in the tested lubricant. To ensure contact of the sample 11 with the counter-sample 12, lower the lever 3 and put the spring 5 of the loading mechanism on the suspension of the force-measuring device 4. Press the "Start" button 27 to turn on the engine 14, while through the first belt drive 16 to the pulley 17, through the second half-shaft 18 and the clutch limiting moment 15, through the secondary half shaft 13, rotation begins to be transmitted to the counter-sample 12. By rotating the handle 9 through the screw 6, the nut 7, combined with the slide 8, is moved downward. The slide 8, moving, stretches the spring 5, thereby applying a load to the suspension of the force-measuring device 4, which through lever 3 it is transferred to sample 11 and counter-sample 12.

An increase in the load in a pair of friction sample 11 - counter-sample 12 leads to an increase in the friction force and, as a consequence, the rotation speed of counter-sample 12 becomes not constant and may even decrease significantly. The speed controller 19 with feedback from the tachogenerator 21 compensates for the change in the rotation speed of the counter sample. The tachogenerator 21, connected to the first half-shaft 13 by the second belt transmission 22, generates an EMF, which is proportional to the rotation speed of the secondary half-shaft 13, and accordingly to the rotation speed of the counter-sample 12. The speed controller 19 monitors the change in the EMF value and accordingly proportionally changes the current supplied to the engine, by adjusting the rotation speed of its shaft, and accordingly through the first belt drive, the rotation speed of the counter-sample is stabilized.

As the load in the friction pair increases, a moment comes when the friction force reaches the limit value - a scuffing occurs, the limiting torque clutch 15 is triggered, while the tachogenerator 21, connected to the half shaft 13 through the second belt drive, ceases to generate the EMF signal, which fixes the shutdown block 24 and stops supplying a control signal to relay 25, the disconnected relay de-energizes the speed controller 19 and the engine 14 - the counter-sample stops rotating.

After turning off the engine 14, the rotation of the handle 9 is stopped and the readings of the force-measuring device 4 are recorded.

The "Stop" button 27 is intended for emergency shutdown of the friction machine electric motor and is not used during normal operation.

By the value of the maximum readings of the force-measuring device 4, at which the engine stopped, a comparison is made of various lubricants in terms of their antifriction and lubricating properties.

Thus, the use of a loading mechanism in the form of a screw pair ensures smooth and uniform loading of the friction pair, and the engine speed controller with feedback ensures a constant rotation speed of the counter-sample 12 throughout the test. Fixation of the seizure moment upon actuation of the clutch and shutdown of the engine increases the accuracy of the measurement of the limiting friction force in the sample-counter-sample pair. In general, the combination of features ensures high measurement accuracy and reproducibility of lubricant testing conditions.

The elements of the friction machine are in structural and functional unity.

This mobile friction machine is manufactured at VMPAUTO LLC and is successfully used to quickly demonstrate the properties of lubricants. The friction machine is easy to transport and does not take up much space.

Claims (2)

1. A friction machine comprising a body with a loading lever hinged in it, on which a holder with a sample installed in it is fixed, also containing a counter-sample, kinematically connected to the engine, a loading mechanism, a force-measuring device mounted on the loading lever, and a control system that differs the fact that the loading mechanism is a screw pair, including a screw connected to the rotation handle and a nut, which is aligned with the slide connected to the spring, which is connected to the suspension of the force-measuring device, the counter-sample is installed on the first half-shaft and connected to the engine through the limiting torque clutch and the first belt drive, the pulley of which is installed on the second half-shaft, while the engine is connected to the speed controller, which is connected to the first half-shaft through the tachogenerator and the second belt drive, the control system also includes a power supply unit connected to the shutdown unit, relay and Start buttons and "St op ". 2. Friction machine according to claim 1, characterized in that an electronic steelyard is used as a force-measuring device.

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