JPS6259543B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a DC electric compressor in which a compression mechanism is driven by a brushless DC motor.

Conventionally, in this type of DC electric compressor, the rotor position detection mechanism is structurally complex, requires a large installation space, and is expensive.

SUMMARY OF THE INVENTION In view of the above points, it is an object of the present invention to provide a rotor position detection mechanism with a simple and space-saving configuration.

First, the conventional DC electric compressor is shown in Figures 1 and 2.
The diagram will be explained.

1 is a stator having a plurality of stator coils 2, 2, . . . 3 is a rotor made of permanent magnets; 4 is a motor case; the stator 1 is attached to the lower part of the case, and a compression mechanism 5 is attached to the upper part of the case. is installed. Reference numeral 6 denotes a crankshaft having a counterweight 8 supported by a bearing portion 7 of the motor case 4, and the rotor 3 and the compression mechanism 5 are connected by the shaft.

Reference numeral 9 denotes a position detection mechanism using a rotor 3, and this mechanism includes detection elements 13, 13 attached to a wiring board 12 via an annular spacer 11 to a detection element support plate 10 attached to the lower end side of the stator 1. and a rotor position indicator 14 attached to the lower end side of the rotor 3 facing the detection element. The detection element 1
3, a Hall element, a detection coil, etc. are used, and in order to obtain a signal from this detection element, a magnet or magnetic material is used as the rotor position indicating material 14.

Therefore, the structure of the position detection mechanism 9 becomes complicated, and the mounting positions of the detection elements 13, 13 are also subject to structural restrictions.

Therefore, in the present invention, the conventional drawbacks are solved by utilizing a fan-shaped counterweight integrally formed with the crankshaft as a rotor position indicator.

The present invention will be described below with reference to the embodiment shown in the drawings, but the same parts as in the conventional example will be denoted by the same numbers and detailed explanation will be omitted.

Reference numeral 1 denotes a stator having a stator coil 2, and the stator is fixed to the lower side of a motor case 4. 5
A compression mechanism is fixed to the upper side of the motor case 4, and the compression mechanism is connected by a crankshaft 6 to a rotor (not shown) made of a permanent magnet.

8 is a fan-shaped counterweight formed integrally with the crankshaft 6, and point C is the center line of the crankshaft 6.

Reference numeral 10 denotes an annular detecting element support plate provided on the upper surface of the motor case 4 so as to surround the counterweight 8, and a vertical piece 10a of the support plate has a wiring board 12 interposed therebetween and a 120° angle on the inside thereof. Three detection elements 13, 13, 13 are arranged concentrically with the counterweight 8 at intervals. The detection elements 13, 13, 13 use a detection coil formed by winding a coil around a core material, and the inductance changes due to the influence of the counterweight 8 made of cast iron or the like. Further, the detection elements 13, 13, 13 are electrically connected to the wiring board 12, and the wiring is taken out from the back side of the wiring board 12 by cutting a part of the detection element support plate 10, such as the vicinity of the detection elements 13, 13, 13. It is.

The detection elements 13, 13, 13 detect the presence or absence of the counterweight 8 having a set conduction angle (for example, 120 to 180 degrees) by a change in inductance, and extract a rotational position signal.

When a Hall element is used as the detection element 13, by attaching a magnet or the like to the outer peripheral surface of the counterweight 8, a rotational position signal can be extracted by the voltage generated in the Hall element.

As described above, the DC electric compressor according to the present invention has a rotor made of permanent magnets and a plurality of stator coils, and is connected to a DC power source through each switching circuit of the stator coils, and the plurality of stator coils are sequentially connected to a DC power source through each switching circuit of the stator coils. It is composed of a brushless DC motor that is energized and a compression mechanism driven by the motor, and the rotational position detection mechanism of the rotor utilizes a counterweight of the crankshaft of the compression mechanism, and the rotational position detection mechanism uses a counterweight of the crankshaft of the compression mechanism, and Since the rotational position signal is extracted by multiple position detection elements installed in the rotor, the rotor rotational position detection mechanism is simple and space-saving, making it easy to integrate into the compressor. This has practical benefits such as making electric compressors cheaper.

[Brief explanation of the drawing]

Figure 1 is a side view of the main parts of a conventional DC electric compressor in which the rotational position is detected by a rotor, Figure 2 is a longitudinal sectional view of the main part of Figure 1, and Figure 3 is the rotational position detected by a counterweight. FIG. 4 is a plan view of the main part of the DC electric compressor of the present invention, FIG. 5 is a plan view of the main part of FIG. 4 excluding the compression section, and FIG. 6 is the plan view of FIG. - is a sectional view taken along the arrow. DESCRIPTION OF SYMBOLS 1... Stator, 3... Rotor, 5... Compression mechanism, 8... Counterweight, 6... Crankshaft, 13, 13, 13... Detection element.

Claims (1)

[Claims] 1. A brushless DC motor that has a rotor made of a permanent magnet and a plurality of stator coils, is connected to a DC power source through each switching circuit of the stator coil, and the plurality of stator coils are sequentially energized; The rotational position detection mechanism of the rotor utilizes a counterweight of the crankshaft of the compression mechanism, and a plurality of position detection elements installed concentrically with the counterweight detect the rotation position of the rotor. A DC electric compressor characterized by extracting a position signal.