JPS6022478B2 - DC motor rectifier - Google Patents

Description

[Detailed description of the invention] This invention relates to a rectifying device for a DC motor.

In rectifying the secondary DC motor, as shown in Fig. 1, a resistor 3 is inserted in series with the brush branch piece 2 that presses against the commutator segment 1, and the current is gradually reduced when the winding 4 is cut. There are some that suppress surge voltage. However, in order to slow down the change in the current flowing through the winding 4, the brush branch piece 2
The number of pieces is huge, making it difficult to manufacture. Furthermore, if the number of brush branch pieces 2 is reduced, the current changes stepwise and sparks are generated each time. Further, if the brush branching piece 2 is structured to instantaneously short-circuit the slit between the segments 1, large sparks are likely to be generated by the branching piece that is cut last. SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a rectifying device for a DC motor that is easy to manufacture and generates few sparks.

A block diagram of an embodiment of the rectifying device of the present invention is shown in FIG.

This is because the main brush pieces 8, 9 and the auxiliary brush pieces 10, 11 are in pressure contact with the segments 5, 6, 7 of the cylindrical commutator, and the main arm
Zener diodes 12 and 13 are connected between the child pieces 8 and 9 and the auxiliary brush pieces 10 and 11, respectively. Windings 14, 15, 16 are connected to segments 5, 6, 7,
Insulators 17, 18, and 19 are interposed. The contact surfaces of the main peonies 8 and 9 are bifurcated. FIG. 3 is a developed view of the rectifier shown in FIG. 2. In FIG. 3, main brush piece 9 short-circuits winding 15 from segment 6 to segment 7.
4, a surge voltage is generated in the winding 15 as shown in FIG.
As shown in the figure, the voltage is suppressed to the Jenner diode voltage Vo. When the voltage of the winding 15 becomes lower than Vo, the resistance of the Zener diode 13 increases, and no current flows through the Zener diode 13. That is, as shown in FIG. 6, when the auxiliary stiffener piece 11 separates from the segment 6, no current flows through the auxiliary brush piece 11, and the current flows from the segment 7 to the main brush piece 9 to the Zener diode 13 to the auxiliary brush piece 11 to the segment 6. → Winding 14 → Main hemp U-piece 8 → The resistance of the Jenner diode 13 on the path of one terminal increases, the current flowing through the winding 14 decreases, and the surge voltage also decreases. In this case, if the width of the auxiliary brush pieces 10, 11 is wider than the inter-segment slit, a surge voltage is generated because the windings 14→16 are short-circuited. Therefore, the auxiliary brush piece 10,1
1 is required to be narrower than the intersegment slit. FIG. 7 is a plan view of an example in which the present invention is applied to a rectifying device using a flat plate commutator.

Since this device is simply a flat plate version of the device shown in FIG. 2, parts corresponding to those shown in FIG. Note that although a Jenner diode is used in this embodiment, a non-linear resistance element such as a varistor may also be used.

As described above, in the rectifying device of the present invention, a non-linear resistance element is connected between the main brush piece and the auxiliary brush piece of the rigid body, and the width of the auxiliary seat U piece is made smaller than the inter-segment slit. It has the following advantages.

m Since current flows through the resistance element only when switching the winding current, an element with a high L operating voltage is not required.

That is, it is possible to use elements with a low operating voltage, and conversely, it is possible to flow a large amount of conduction current, and it is possible to suppress the generation of surge voltage and sparks. If it is inserted between the windings, it is regulated by the power supply voltage, the current consumption is small, and the surge voltage is also higher than the power supply voltage. {2} The lower the operating voltage of a nonlinear element such as a Zener diode or a varistor diode, the more current it can flow, which is a disadvantage for absorbing surge voltage.

[3] In the case of a 3-pole motor, if you connect a spark absorbing element such as a capacitor or varistor between the windings, you will need three.
In this invention, two pieces are sufficient.

[41] There is no need to connect to the rotating part of the winding or commutator segment, simplifying the manufacturing process.

Waki: Even if the rotor shape becomes smaller, there are no restrictions on the elements used.

■ The size of the element used is 4 mm.

'7} Unlike a cosodenser, it does not cause current or voltage to oscillate.

'81 The auxiliary brush piece that is switched last does not short-circuit the inter-segment slits, and the characteristics of a non-linear resistance element can be fully exhibited.

{9} There is no need to extremely increase the number of brush pieces.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of a conventional example, Fig. 2 is a block diagram of an embodiment of the rectifier of the present invention, Figs. 3 to 6 are explanatory diagrams of its operation, and Fig. 7 is a structure of another embodiment. It is a diagram. 5-7...Segment, 8,9...Main Sakakishi piece "
107 11... Auxiliary brush piece, 12, 13... Jenner diode.
Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7

Claims (1)

[Claims] A main brush piece, an auxiliary brush piece that moves relatively on a commutator surface following the main brush piece, and a nonlinear resistance element connected between the main brush piece and the auxiliary brush piece, A DC motor rectifier in which the width of the brush pieces is set smaller than the slits between commutator segments.