JPS6022477B2 - brush device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a brush device such as a DC motor.

Conventional brush devices use low-resistance brushes made by mixing carbon with metal powder to facilitate the flow of current, as shown in Figure 1, in order to suppress the fire that occurs when crossing the commutator segments. A carbon-only brush mouth is pasted and housed in an insulating holder so that it can be raised and lowered, and the brush with a small resistance value crosses the insulation slit S between segments g and g of commutator ○ first, and the brush mouth connects to the coil L. When cutting, the resistance value increases, reducing the current and suppressing surge voltage.

However, it is impossible to increase the resistance value with just the carbon of the brush mouth due to the material, and it is not possible to suppress the current to the required value.Furthermore, when the brush mouth cuts segment g, it short-circuits the coil L, resulting in a large Since a surge voltage is generated, sparks cannot be sufficiently suppressed. SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a brush device that can sufficiently absorb the surge voltage generated when the brush crosses a commutator segment and can sufficiently suppress sparks.

The brush device of the first invention includes a main power bong brush that is wider than the insulating slit between the segments and whose lower end faces the commutator, and a main power bong brush that is narrower than the insulating slit and located behind the main power bong brush in the commutator rotation direction. a sub carbon brush which is arranged apart from the main carbon brush and whose lower end faces the commutator; an insulator having upper ends of the main and sub carbon brushes fixed to the lower surface thereof; and an insulator buried in an exposed state under the insulator. a resistor in contact with the main and sub carbon brushes; a conductive layer formed from the upper surface of the insulator to the lower surface to which the main carbon brush is fixed; An insulating holder that accommodates a layered object that can be raised and lowered freely, and
The brush device of the second invention is characterized in that it is configured to include a conductive spring that comes into contact with the conductive layer on the upper surface of the insulator and presses the integral body against the commutator. a main power pump brush which is wide and has a lower end facing the commutator; and a main power pump brush which is narrower than the insulating slit and is arranged behind the main power pump brush in the commutator rotation direction and separated from the main power pump brush and whose lower end faces the commutator. A secondary carbon brush facing each other, an insulator having the upper ends of the main and secondary carbon brushes fixed to its lower surface, a resistor sandwiched between the upper parts of the main and secondary carbon brushes, and the main force extending from the upper surface to the lower surface of the insulator. - a conductive layer formed over the fixed surface of the carbon brush; an insulating holder that accommodates the integrated body of the main and sub carbon brushes, an insulator, a resistor, and the conductive layer so as to be movable up and down; and a conductive layer on the upper surface of the insulator. The commutator is characterized in that it is configured to include a conductive spring that contacts and presses the integral body against the commutator.

With this configuration, it is extremely easy to assemble the motor, etc., and costs can be reduced, and the motor, etc. can be made smaller. An embodiment of the brush device of this invention is shown in FIG.

In Fig. 2, A and B are the main carbon brush and the secondary carbon brush, which are made by dividing the carbon brush into two.The main carbon brush A is made wider than the insulating slit S between the segments g and g of commutator B is formed narrowly. R is a resistor that is partially exposed and buried in one surface of the insulator J and electrically connected with conductive layers on both sides, and the main Bonpla brush A and the sub carbon brush B are placed opposite each other with a gap e. A resistor R is placed on the top surface so that both are connected electrically, and they are fixed together and housed in an insulating holder that can be moved up and down within the day.A conductive layer and a conductive fin spring P are placed on the top surface of the conductive layer. A brush device is constructed by configuring a cylindrical brush that supplies power only to A, and bringing this cylindrical brush into elastic contact with a commutator D such that the main power bomb brush A crosses the slit S between the segments first. . The brush device shown in FIG. 2 has an electrical configuration as shown in FIG. 3.

Therefore, while the coil L is short-circuited, the short-circuit current flowing to the brush does not increase due to the carbon, and the main force - the bon brush A.
The surge voltage generated when the sub carbon brush B cuts the coil L is absorbed by the resistor R, and when the sub carbon brush B cuts the coil L, the current is suppressed by the resistor R and no large surge voltage is generated. In Figure 4, instead of embedding a resistor R in an insulator J, it is interposed between a wide main carbon brush A and a narrow carbon brush B, and the resistor R is connected to the conductive spring P. This is another embodiment in which a cylindrical brush is configured to supply power only to the main power supply brush A.

In the case of this embodiment as well, the same effects as in the case of FIG. 2 can be expected. As described above, in the brush device of the present invention, the main carbon brush and the secondary carbon brush are arranged in front and back relative to the direction of rotation of the commutator, the tips of both brushes are brought into contact with the commutator, and a resistor is placed between the two base ends. Because it is a configuration in which the two brushes are connected, the resistance value between the tips of both brushes can be made sufficiently high. Moreover, since the sub carbon brush is made narrower than the insulating slit, the Toyama carbon brush will not short-circuit the coil. Sparks can be sufficiently suppressed.

In addition, since the main carbon brush, secondary carbon brush, and resistor are fixed together, assembly of the motor etc. is extremely easy and costs can be reduced.
There is no need for a separate means for fixing the resistor, and there is no possibility of wire breakage due to vibration. Furthermore, since the brush and the resistor are placed in the same location, the motor etc. can be made smaller without taking up any extra space. FIG. 3 is a schematic diagram showing one embodiment, FIG. 3 is an electric circuit diagram thereof, and FIG. 4 is a schematic diagram showing another embodiment of the present invention.

A...Main Bonplash, B...Secondary carbon brush, R
...Resistor, day...Insulation holder, etc.
...Conductive layer, D... Commutator, G...
...Segment, S...Insulation slit.

Figure 1 Figure 2 Figure 3 Diagram

Claims (1)

[Claims] 1. A main carbon brush that is wider than the insulating slits between the segments and whose lower end faces the commutator, and a main carbon brush that is narrower than the insulating slits and is located rearward of the main carbon brush in the commutator rotation direction. a sub carbon brush that is arranged apart from the main carbon brush and whose lower end faces the commutator;
an insulator to which the upper ends of the main and sub carbon brushes are fixed; a resistor buried in an exposed state under the insulator and in contact with the main and sub carbon brushes; a conductive layer formed over the fixed surface of the main carbon brush; an insulating holder that accommodates the integrated body of the main and sub carbon brushes, an insulator, a resistor, and a conductive layer such that it can be raised and lowered; and an upper surface of the insulator. a conductive spring that comes into contact with a conductive layer of the body and presses the integral body against the commutator. 2. A main carbon brush that is wider than the insulating slit between the segments and whose lower end faces the commutator, and a main carbon brush that is narrower than the insulating slit and is spaced apart from the main carbon brush behind the main carbon brush in the commutator rotation direction. a resistor sandwiched between an insulator having upper ends of the main and sub carbon brushes fixed to the lower surface thereof and the upper parts of the main and sub carbon brushes; a conductive layer formed from the upper surface of the insulator to the lower surface to which the main carbon brush is fixed; and an insulator that accommodates the integrated body of the main and sub carbon brushes, the insulator, the resistor, and the conductive layer so as to be movable up and down. holder and
a conductive spring that comes into contact with a conductive layer on the upper surface of the insulator and presses the integral body against the commutator.