JPS6229754U - - Google Patents

Description

[Brief explanation of the drawing]

Fig. 1 is a vertical sectional view showing an embodiment of the present invention, Fig. 2 is a reduced plan view showing the same embodiment with the sensor removed, Fig. 3 is a plan view of the above embodiment, and Fig. 4 is a plan view of the above embodiment. FIG. 5 is a plan view showing another example of the encoder disk that can be used in the present invention, and FIG. 6 is a plan view showing the sensor used in the above example. FIG. 7 is a circuit diagram showing an example of a detection circuit that can be used in the present invention, and FIG. 8 shows changes in the positional relationship between the encoder disk and the sensor to explain the operation of the above embodiment. FIG. 9 is a timing chart of the detection signal to explain the operation of the above embodiment, FIG. 10 is a torque characteristic diagram to explain the operation of the above embodiment, and FIG. 11 is the same torque characteristic. FIG. 12 is a plan view showing the positional relationship between the encoder disk and the sensor corresponding to the embodiment of FIG. 11;
FIG. 13 is a plan view showing another example of an encoder disk that can be used in the present invention, FIG. 14 is a plan view showing another example of an encoder disk and rotor magnet that can be used in the present invention, and FIG. 15 is a timing chart showing detection signals obtained by the encoder disk of FIG. 14; FIG. 18...shaft, 20...rotor, 21, 22, 41
, 43...Encoder disk.

Claims (1)

[Scope of utility model registration request] A small electric motor characterized in that an asymmetrical encoder disk is attached to the axial side of the rotor so that it has a certain relationship with the magnetic poles of the rotor and rotates integrally with the rotor.