JPH0590875U - Brush wear detector for rotating electric machine - Google Patents

Abstract

(57) [Abstract] [Purpose] Providing a brush wear detection device for rotating electrical machines that does not require processing of the brush holder or wiring to the brush holder, and wiring is simple and operation is reliable only by processing the brush body. To do. [Structure] The two conductive wires 6 are spaced at least in the direction of rotation of the commutator by a distance larger than the insulation distance between the commutator pieces,
Each conductive wire 6 is embedded in the brush main body 1 via an insulator 7.
When the brush is worn and the two conductive wires 6 come into contact with the commutator surface A, the other end of is connected to the alarm device 9, and the alarm device 9 is activated by the rectification electromotive force generated between the commutator pieces. Brush wear detection device for rotating electric machine.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a brush wear detecting device for a rotating electric machine.

[0002]

[Prior Art]

 An example of a conventional device of this type is shown in Japanese Utility Model Publication No. 36-6618. FIG. 2 shows its structure. 1 is a brush main body, 2 is a brush holder, 3 is a brush pressing metal fitting, 4 is a pressure contact spring, 5 is a brush, which is installed in parallel with the brush holder 2 and is guided into the brush holder 2. The auxiliary electrode is composed of a conductive wire 6 facing the commutator surface A and an insulating coating 7 surrounding the conductive wire 6 at a position almost equal to the wear limit of the brush 1, and particularly near the upper part of the brush 1. An engaging portion 8 for engaging the protrusion 5 is formed. Reference numeral 9 is an alarm device connected and inserted between the brush pressing member 3 and the auxiliary electrode 5, 10 is a resistor connected in series with the alarm device, and 11 is a power supply, which forms a brush wear alarm circuit. When the brush 1 reaches the wear limit, the conductive wire 6 comes into contact with the commutator surface A, and the circuit is closed to issue a display or alarm.

[0003]

[Problems to be solved by the device]

 The brush wear detection device described above requires two lines of voltage, one for driving the rotating electric machine and the other for the power supply voltage for the alarm device circuit. There is a problem that the contact area of the moving brush becomes small and the current density of the brush becomes high. In addition, it is necessary to form an engaging portion that engages with the protrusion of the auxiliary electrode, which complicates brush processing. It is an object of the present invention to provide a brush wear detecting device for a rotary electric machine that solves the above-mentioned drawbacks.

[0004]

[Means for Solving the Problems]

 According to the present invention, two conductive wires are embedded in the brush main body through an insulator at a distance at least larger than the insulating distance between the commutator pieces in the rotating direction of the commutator, and the other end of each conductive wire is connected. A brush for a rotating electric machine, which is connected to an alarm device and which activates the alarm device by rectifying electromotive force generated between the commutator pieces when the brush is worn and the two conductive wires come into contact with the commutator surface. A wear detector.

In the present invention, as the conductive wire to be embedded in the brush body, a Teflon- or vinyl-coated annealed copper wire, a copper powder, a silver powder or the like filled in a vinyl pipe and solidified is used. The tip to be embedded in the brush body is fixed to copper wire by melting Teflon or vinyl, or an adhesive is inserted between the copper wire and those insulators to fix both, and the conductive wire is attached to the brush body. Insulate to prevent contact. In this method, a hole up to the wear limit is bored in the brush body, and a conductive wire whose tip is insulated is inserted and fixed. The other end of the conductive wire is connected to the alarm device. The distance between the two conductive wires to be embedded is made larger than the insulation distance between the commutator pieces, and at least the rectification electromotive force generated between the adjacent commutator pieces is sensed.

With the above structure, when the brush is worn to the limit of wear and two conductive wires come into contact with the commutator surface, the commutation electromotive force passes through the two conductive wires and an alarm device such as a lamp or a buzzer. The alarm device is activated. In the above, it is preferable that the alarm device is a light emitting diode, is installed inside the rotating electric machine, and is connected to the optical fiber cable because the brush replacement time can be known without going to the connecting place of the rotating electric machine. Further, when the rectifying electromotive force is small, it is possible to detect the brush wear with high reliability by providing an amplifier circuit.

[0007]

【Example】

 Next, an embodiment of the present invention will be described. FIG. 1 is a diagram showing a main part of a brush wear detecting device for a rotary electric machine according to an embodiment of the present invention. The rotating electric machine is a DC electric motor for electric trains, the insulation distance between the commutator pieces is 0.8 mm, the width of the commutator piece is 4.5 mm, and the brush is 2 x (thickness 10, width 40, height 50) mm. The distance between the two conductive wires was 15 mm. In the figure, 1 is a brush main body, 2 is a brush holder, 2 conductive wires 6 are annealed copper wires, 30 pieces of 0.18 mm in diameter are gathered, and a 0.4 mm thick vinyl insulation coating 7 is provided. It was done. Make two holes with a diameter of 2 mm in the brush body 1 at intervals of 15 mm in the direction of rotation of the commutator. Insert the conductive wire 6 with its tip melted and insulated into each hole and glue it. Fixed A light emitting diode alarm device 9 was connected to the other end of the conductive wire 6.

In this way, as the brush body 1 wears, when the conductive wire 6 whose tip is insulated is displaced to the commutator surface A and reaches the wear limit, the insulation of the tips of the two conductive wires 6 wears. Then, the annealed copper wire comes into contact with the commutator surface A, the circuit is closed, and the rectifying electromotive force generated between the commutator pieces causes the light emitting diode to illuminate, so that it is possible to know when to replace the brush.

[0009]

[Effect of the device]

 The brush wear detecting device of the present invention uses the minute rectification electromotive force of the rotating electric machine, so that there is no danger, and there is no need to use a separate power source, and the wiring is simple. In addition, the brush contact area does not become small during practical use, the brush wear limit can be reliably detected, and damage to the commutator surface due to excessive brush wear can be prevented.

[Brief description of drawings]

FIG. 1 is a diagram showing a main part of a brush wear detecting device for a rotating electric machine according to an embodiment of the present invention.

FIG. 2 is a diagram showing a main part of a conventional brush wear detection device for a rotary electric machine.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Brush main body, 2 ... Brush holder, 3 ... Brush pressing metal fitting, 4 ... Pressure contact spring, 5 ... Auxiliary electrode, 6 ... Conductive wire, 7 ... Insulating coating, 8 ... Engaging portion, 9 ... Alarm device 10 ... Resistance , 11 ... Power supply

Claims (1)

[Scope of utility model registration request] 1. The two conductive wires are embedded in the brush main body through an insulator at a distance larger than the insulation distance between the commutator pieces in the rotation direction of the commutator, and the other end of each conductive wire is provided. To a warning device, and when the brush is worn and the two conductive wires come into contact with the commutator surface, the commutator electromotive force generated between the commutator pieces activates the warning device. Wear detection device.