SU1739423A1 - Device for testing spring forces in dc machine brush assembly - Google Patents

Abstract

Use: setting the required value of spring force in the brush assembly of direct current machines. Summary of the Invention; The device contains a base, a measuring element, which is connected to a recording device. At the bottom there is a window, the dimensions of which are equal to the size of the brush package. On the base, on the opposite sides, there is a L-shaped clamp and a L-shaped stop. Elastic springs are fixed at one end on the base from the side of the L-shaped clamp. The free end of the elastic springs protrudes above the window. In the places of the greatest spring deflection, the measuring element 1 is installed

Description

The invention relates to electric machines of direct current and can be used to control and regulate the forces of the springs in the brush holders at manufacturing plants and repair shops.

There are known devices for measuring the pressure of the brush on the collector of electrical machines, comprising an electrical measuring device, pressure sensors in the form of an elastic sensitive force-measuring element with field windings and a measuring ball, located in a housing, a metal ball interacting with a sensor, a brush, a brush holder, and sinusoidal voltage sources, two separation capacitors and a loop capacitor, which together with the sensor windings connected in series with the counter windings Compensatory and force-measuring

elements and the primary winding of the first separation resonant circuit, etc. In order to increase the accuracy and sensitivity of the measurement, the sensitive and compensating force-measuring elements and the magnetic circuits of the separation transformers are made of magnetically soft ferrite.

A known method for controlling the forces of the springs in the brush holder, according to which a sensor is connected to the pressure element and a signal proportional to the force is taken into it. In order to increase the accuracy and allow the adjustment of the force of the springs in the brush holder, the pressure element is successively deflected from the nominal position to opposite sides with a force varying 20-50% from the calculated value of the elastic component in the nominal position of the mechanism

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the efforts to return the pressure element to this position with a deceleration of 0.2-0.01 mm / s, compare their actual values with the nominal forces of the respective branches of the hysteresis loop of the elastic characteristics of the brush holder, determine the half-sum of these values as the elastic component, and their half-differences - as the friction component of the specified elastic characteristic, and take these values as the actual values of the specified components.

The drawbacks of the devices are the complexity of the design, the need for each time to measure the pressure of the brush on the collector to pull out the working brushes and install the brushes with the sensor, which is not quite technologically effective at the repair position and reduces labor productivity.

A device for controlling the spring pressure in brush holders is known. It is a hand-held dynamometer that is mainly used in the process of repairing brush holders.

The device is characterized by insufficient accuracy of adjusting the force of the springs and the danger of damage to the fingers, since the possibility of the dynamometer disrupting from the springs of the brush holder is not excluded.

The purpose of the invention is to improve safety and manufacturability during repairs.

The goal is achieved by the fact that in the device for controlling the forces of the springs in the brush assembly of DC electric machines containing a base, a measuring element connected to a recording device, a window is made whose width exceeds the tangential size of the brushes and the axial size of the packet brushes in the holder of the brush holders. The device is equipped with a L-shaped stop and a L-shaped clip fixed on the base from opposite sides of the window along its width by elastic plates fixed at one end on the base from the side of the L-shaped clip so that the free ends of each plate protrude above the window, and the number plates is equal to the number of brushes; a measuring element is installed on the protruding part of each plate in the place of the greatest deflection boom.

The proposed device allows, firstly, controlling the efforts of all the springs in the brush holder at the same time, secondly, dangerous working conditions of the locksmith are eliminated, since the brush holder is installed on the base of the device, fixed with one screw, and the spring force is checked automatically.

The drawing shows the structure of the device.

The device comprises a base 1, in which a window 2 is made, the width of which exceeds the tangential size of the brushes, and the length is the axial size of the package of brushes in the holder of the brush holders. Device

provided with a L-shaped stop 3 and a L-shaped clamp 4, fixed on the base 1 on opposite sides of the window 2 along its width by elastic plates 5, fixed at one end on the base 1 with

side of the l-shaped clamp 4 so that the free ends of each plate 5 protrude above the window 2, and the number of plates is equal to the number of brushes on the projecting part of each plate 5 in place

The largest element of the deflection is mounted on the measuring element 6. The plates 5 are pressed against the base 1 by the overlay 7 and tightened, for example, by bolting. At base 1, there is a conduit channel 8 which terminates in connector 9.

The device works as follows.

The brush holder, which is subject to control and adjustment of the force of the springs, with the brushes pre-fixed in the sockets, is mounted on the base 1 so that its edge, where the brushes are located, is placed in the L-shaped support 3, which fixes the vertical and longitudinal

movement. Using the L-shaped clamp 4, the opposite side of the brush holder is fixed. After that, the brush holders in the slots are removed and the brushes begin to press under the action of

spring-on elastic plate 5 with the measuring elements 6, the second ends of which are fixed. Plates 5 with measuring elements 6 are deformed and signals from them are connected by

wires come to connector 9, from which the communication line goes to the measuring bridge, amplifier and instrument (for example, a serial device IDC-1 - a digital strain gauge with ten measurement channels) can be used as a measuring unit.

The annual savings from the implementation of the device for controlling the spring forces in the brush holders of locomotives consist of the savings in reducing the time spent on adjusting the spring pressure (EP) and the savings in increasing the annual operating time of the locomotive (En)

Ae Ep + En- (Ce + Sam + Sts),

where C is the increase in the cost of electricity consumed by the device;

Himself - the amount of expenses for depreciation of the device;

CTC costs for the current content of the device.

The savings from reducing the time spent on adjusting the spring pressure are determined by

Ep Zp At-Msch.

where Zp is the hourly wage rate of the locksmith - the collector of electrical equipment;

At - reduction of time for setting the pressing of the springs of the brush holders, At «0.4 h;

Msch - the number of brush holders repaired per year.

Save from increasing the annual operating time of locomotives

En tr L Tg N3,

where tr is the expenditure rate for 1 hour of the locomotive;

I - the relative increase in annual operating time, 4%;

Тг - year operating time of the locomotive;

N3 is the number of locomotives in operation.

Claims (1)

Claims An apparatus for monitoring spring forces in a brush assembly of electric machines of direct current, comprising a base, a measuring element connected to a recording device, characterized in that, in order to improve safety and workability during repair, a window is made at the base, exceeds the tangential size of the brushes, and the length is the axial size of the package of brushes in the brush holders, it is equipped with an L-shaped stop and a clip fixed to the base on opposite sides of the window along e width, elastic plates fixed at one end on the base of the L-shaped clamp so that the free ends of each plate protrude above the window, the number of plates is equal to the number of brushes, a measuring element is installed on the protruding part of each plate in the place of the largest deflection.