JPS6237970Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a noise damping structure for a hermetic electric compressor equipped with an accumulator. A conventional electric compressor of this type will be explained with reference to FIG. 1 is a cylindrical airtight container, 2 is a stator of the motor, 3 is a coil, and 4 is a rotor. 5 is a compression mechanism whose drive shaft 6 is connected to the rotor 4;
The stator 2 is crimped to the cylindrical inner wall of the closed container 1, and the compression mechanism 5 is welded and fixed to the cylindrical inner wall of the closed container 1. Reference numeral 7 denotes an accumulator disposed in parallel with the closed container 1, and is supported by the closed container 1 by a support 8. Reference numeral 9 denotes a refrigerant suction port provided horizontally in the closed container 1, and is connected to a vertical refrigerant outlet provided in the bottom end plate 10 of the accumulator 7 by a bent pipe 11. 12 is a discharge pipe for compressed refrigerant.

In the hermetic electric compressor having the above structure, the vibrations of the electric compressor are transmitted to the accumulator 7 via the hermetic container 1 and the bent pipe 11, and at the joint between the bent pipe 11 and the head plate 10 in a direction perpendicular to the axial direction. (horizontal direction) resonance and generate abnormal sound at a specific frequency. In order to prevent this abnormal noise from occurring, the rigidity of the vibration system is adjusted by changing the material and dimensions of the head plate 10, or by attaching a damper 13 to the body of the accumulator 7 as shown in FIG. Although it has been attempted to prevent resonance from occurring in a specific frequency range by There's a problem.
The present invention aims to solve this problem by extremely simple means.

An embodiment of the invention will be described with reference to FIG. In the figure, 1 to 12 indicate the same parts as in FIG. 1. The feature of the present invention is that the end plate 10 of the accumulator 7 has a plurality of apertures 1 as shown in FIG.
4 radially from the center. By appropriately setting the number, length, width, and depth of the aperture 14, the resonance frequency of the vibration at the joint between the end plate 10 and the curved tube 11 can be moved from a specific frequency range where the vibration is large. As a result,
Noise can be reduced.

Fig. 4 shows that an accumulator 7 formed of a rigid plate with an outer diameter of 75 mm and a plate thickness of 2 mm is fixed as shown in a sealed container 1 containing an electric compressor with an output of 500 W to 1500 W. In a vibration system connected by a curved tube 11 formed of a copper plate with a thickness of 1 mm, a length of 20 mm is connected to the end plate 10 of the accumulator 7.
When eight orifices 14 with a width of 3 mm, a width of 3 mm, and a depth of 3 mm are provided radially, and vibration is applied in the radial direction at right angles to the axis of the closed container 1 near the suction port 9 of the closed container 1, the vibration direction is This is a graph showing the vibration response characteristics of the side wall of the accumulator in the same direction, with the vibration response level (acceleration/force) on the vertical axis and the frequency on the horizontal axis. In the figure, the solid line shows the characteristics of the vibration system of the present invention in which the diaphragm 14 is provided on the end plate 10, and the dotted line shows the conventional vibration system without the diaphragm 14. In this vibration response characteristic, the frequency range of 800~1500Hz and 2500~3500Hz is
The Hz frequency range is 500 Hz of the excitation force generated when the electric compressor is operated at a power frequency of 50 Hz or 60 Hz.
This is a high frequency component of Hz or higher, which is a frequency range in which vibration is particularly large, and is considered to be an important cause of noise generation. In the present invention (solid line), the vibration response level is generally reduced in this frequency range, and the part with a high vibration response level, that is, the resonant part, is in another frequency range (1800
Hz).

Figure 5 is a graph showing the noise frequency characteristics of a hermetic electric compressor.The electric compressor of the present invention (solid line) has a lower sound pressure level at frequencies around 1250Hz compared to the conventional electric compressor (dotted line). It can be seen that

As described above, the hermetic electric compressor of the present invention houses the electric motor and the compression mechanism 5 integrally connected to the electric motor inside the hermetic container 1, and the accumulator 7 arranged in parallel with the hermetic container 1. The end plate 10 of the accumulator 7 is supported by the airtight container 1 and has a structure in which the refrigerant outlet of the end plate 10 at the bottom of the accumulator 7 is connected to the refrigerant suction port 9 of the airtight container by a bent pipe 11.
The present invention is characterized in that a plurality of apertures 14 are provided radially from the center, and the plurality of apertures 14 are such that when the electric compressor is driven, the resonant frequency of vibrations generated in the accumulator 7 is reduced to noise. The number, length, width, and depth of the noise are set so as to transition from a frequency range with high noise to a frequency range with low noise. Therefore, an excellent effect of reducing the noise of the hermetic electric compressor can be achieved by the extremely simple means of appropriately determining the dimensions of the orifice 14.

[Brief explanation of the drawing]

Figure 1: Longitudinal cross-sectional view of a conventional hermetic electric compressor.
Figure 2: Longitudinal cross-sectional view of the hermetic electric compressor of the present invention,
Fig. 3: A plan view of the end plate of the accumulator of the present invention, Fig. 4: A graph showing the vibration response characteristics of the accumulator, Fig. 5: A graph showing the relationship between the vibration frequency and noise of the hermetic electric compressor. Symbol, 1... airtight container, 2... stator, 3...
Coil, 4...Rotor, 5...Compression mechanism, 6...
Drive shaft, 7...Accumulator, 8...Support,
9... Suction port, 10... End plate, 11... Bent pipe, 1
2...Discharge port, 13...Damper, 14...Aperture.

Claims (1)

[Claims for Utility Model Registration] (1) An electric motor and a compression mechanism integrally connected thereto are housed inside a closed container, and an accumulator arranged in parallel with the closed container is supported by the closed container. In addition, in a structure in which a refrigerant outlet provided on a bottom end plate of the accumulator is connected to a refrigerant suction port of the sealed container by a bent pipe, a plurality of throttles are provided in the end plate of the accumulator radially from the center. A hermetic electric compressor characterized by: (2) The number and length of the plurality of throttles are set such that when the electric compressor is driven, the resonance frequency of vibrations generated in the accumulator shifts from a frequency range with high noise to a frequency range with low noise.
A hermetic electric compressor according to claim (1) for utility model registration, characterized in that the width and depth are set.