RU2399999C1 - Method for measurement of gas mains destruction parametres and complex for its realisation - Google Patents

Abstract

FIELD: electricity. ^ SUBSTANCE: device is composed of the following components: brush holder with pressing finger, brush, body rigidly connected to it, power measuring element of force sensor with excitation and measurement windings. Power measuring element is divided into four sectors by mutually perpendicular axes shifted relative to its central axes along the line of forces action by the angle of 45 degrees, and excitation and measurement windings are laid into them, embracing section of power measuring element. At the same time all windings are connected to form bridge measurement circuit, and protective element is arranged in the form of flat spring. ^ EFFECT: improved sensitivity, accuracy of measurement, expansion of functional capabilities, both static and dynamic ones, and simplified design of device. ^ 1 dwg

Description

The invention relates to electrical engineering, in particular to devices for measuring brush presses on the collector directly on an electric machine in operating mode.

A device is known for measuring brush presses on the collector of an electric machine, comprising a brush, brush holder, an annular magnetic circuit with field windings and a measuring one, which is located in the housing and rigidly connected to the brush, installed in the brush holder of the machine all the way to the collector, while the annular magnetic circuit through a steel ball and a protective spring is connected to the pressure ring of the brush holder (AS USSR No. 828280, class H01R 39/58, publ. 07.05.81, BI No. 17, "Device for measuring brush pressure on the collector of electrical machines", author Ora Dubinin A.E. et al.).

The device has low sensitivity and accuracy due to the measurement of only the compression force, has large dimensions due to the use of the compensation element and cannot be used on a working electric machine, as it is intended only for brush holder monitoring.

A device is known for measuring brush presses on the collector of electric machines, comprising a brush holder with a finger, a brush and a housing rigidly connected to it, housed in a brush holder, a force measuring element located in the housing with excitation windings and a measuring one, while the sensitive force measuring element of the force sensor is connected through a metal ball and a spring with a movable part of the device interacting with a push finger. (AS USSR No. 919004, class. H01R 39/58, published 07.04.82, BI No. 13, “Device for measuring brush pressure on the collector of electric machines”, authors A. Dubinin and others).

A disadvantage of the device for measuring brush presses on the collector of electric machines is the low sensitivity and accuracy due to the measurement of only the compressive stress and has large dimensions due to the use of the compensation element.

This technical solution was made by the authors as a prototype.

The technical result is to increase the sensitivity, measurement accuracy, expand the functionality of both static and dynamic, and simplify the design of the device.

The technical result is achieved by the fact that in the device for measuring brush presses on the collector of electric machines, comprising a brush holder with a finger, a brush and a housing rigidly connected to it located in a brush holder, a force measuring element of a force sensor with excitation and measuring windings located in the housing, the force measuring element of the force sensor is connected through the protective element with the movable part of the device interacting with the push finger, the force measuring element is divided into four sectors mutually perpendicular axes shifted relative to its central axes along the line of action of the forces by an angle of 45 degrees, and laid in them, covering the cross section of the force measuring element, the field windings and measuring, while all windings are connected, forming a bridge measuring circuit, and the protective element is made in the form flat spring.

The drawing schematically shows the proposed device.

A device for measuring brush presses on the collector of electric machines contains a brush holder 1 with a finger 2, a brush 3 and a housing 4 rigidly connected to it, located in the brush holder 1, and a force measuring element 5 with windings 6 located in the housing 4, a metal ball 7, a support bar 8, spring 9, pressure plate 10, adjusting screws 11.

The device operates as follows.

The supply signal U1 is supplied to the bridge measuring circuit formed by the windings 6. If there is no external force acting on the pressure plate 10, the bridge electrical circuit of the device is balanced and the signal U2 at the output is zero. Under the action of external force on the pressure plate 10, the pressure from it is transmitted through the spring 9, the support plate 8 and the metal ball 7 to the elastic element 5. Under the action of the pressure force in the force measuring element 5, mechanical compressive and tensile stresses arise in mutually perpendicular planes, leading to compression of the ring in the upper and lower sectors and stretching in the lateral sectors. The magnetic permeability of the upper and lower segments of the ring during compression decreases, and the magnetic permeability of the side segments increases with tension. Since the corresponding windings are included in the adjacent shoulders of the bridge circuit, a signal U2 proportional to the pressing force will appear at its output.

The spring 9 is pre-compressed with guide screws 11 with a force the value of which is less than the tensile strength of the force measuring element 5 (ferrite ring), but higher than the maximum measured force.

When striking the pressure bar 10, the protective spring 9 is compressed and the pressure bar 10 is lowered to its stop in the upper edge of the housing 1. Thus, the load-measuring element 5 is protected from impacts on the pressure bar 10.

The proposed device for measuring brush pressure on the collector of electrical machines will increase the sensitivity and measurement accuracy by at least two times due to the simultaneous measurement of compression stresses and tensile stresses in both static and dynamic modes.

Claims (1)

A device for measuring brush pressure on the collector of electrical machines, comprising a brush holder with a finger, a brush and a housing rigidly connected to it, housed in a brush holder, a force measuring element of the force sensor with excitation and measuring windings, while the force measuring element of the force sensor is connected through a protective an element with a movable part of the device interacting with a push finger, characterized in that the force measuring element is divided into four sectors mutually perpendicular axes shifted relative to its central axes along the line of action of the forces by an angle of 45 °, and laid in them, covering the cross section of the force measuring element, field windings and measuring, while all windings are connected forming a bridge measuring circuit, and the protective element is made in the form of a flat spring .