JPS5898678A - Vibration insulating device for enclosed type motor compressor - Google Patents

Abstract

PURPOSE:To reduce noise by a method wherein a vibration insulating ring of metal, connecting the inner surface of a mirror plate for an accumulator and a tube extending into the interior of the accumulator closely, is arranged in the captioned device equipped with the accumulator. CONSTITUTION:The accumulator 7 is supported by an enclosed vessel 1 through a supporter 8 and the curved tube 11 attached to the accumulator is connected to the suction port 9 of the enclosed vessel 1. The vibration insulating ring 14 of metal is fixed at the connecting part between the accumulator 7 and the inner surface of the mirror plate 10. The resonance frequency of the vibration at the connecting part of the mirror plate 10 and the curved tube 11 may be shifted to a specified frequency having a large vibration by setting the diameter and the thickness of the ring 14 properly, as a result, noise may be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vibration isolating device 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. Reference numeral 5 denotes a compression mechanism, the drive shaft 6 of which 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 connected to the cylindrical inner wall of the closed container 1. Fixed by welding. 7 is an accumulator arranged 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 airtight container 1;
It is connected by a bent pipe 11 to a vertical refrigerant outlet provided at the bottom. 12 is a discharge pipe for compressed refrigerant.

In the hermetic electric compressor having the above structure, 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 end plate 1o, or by attaching a damper 13 to the body of the accumulator as shown in Figure 1. Although it has been attempted to prevent resonance from occurring in a specific frequency range by
There are also various difficult problems in terms of cost. 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. 14
is a metal member provided in the joint portion of the curved tube 11 having a straight portion in the accumulator γ and having an open upper end and the inner surface of the end plate 1o of the accumulator 7, and fixed in close contact with the inner surfaces of the curved tube 11 and the end plate 10. By appropriately setting the diameter and thickness of the anti-vibration ring (Fig. 3) made of
The resonant frequency of the vibration at the joint between the curved pipe 11 and the curved pipe 11 can be moved from a specific frequency range where vibration is large, and as a result, noise can be reduced.

In FIG. 4, an accumulator 7 formed of a steel 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 sooo~1500 W.
In a vibration system in which these are connected by a curved tube 11 made of a copper plate with an outer diameter of 14 mm and a plate thickness of 1 mfn, a vibration isolating ring 14 of the present invention made of steel with a diameter of 30 mm and a thickness of 5 mm is connected to the curved tube 11 and the mirror plate 1o. This shows the vibration response characteristics of the side wall of the accumulator in the same direction as the excitation direction when the accumulator is fixed to the joint of the closed container 1 and radial vibration is applied at right angles to the axis of the closed container near the suction port 9 of the closed container 1. In the graph, the vertical axis shows the vibration response, the bell (acceleration/force), and the horizontal axis shows the frequency. In the figure, the solid line shows the characteristics of the vibration system of the present invention equipped with the vibration isolation ring 14, and the dotted line shows the conventional vibration system without the vibration isolation ring 14. In this vibration response characteristic,
Frequency range of 800-1500Hz and 2600-35
00Hz frequency range, electric compressor is 50Hz or 5o
5 of the excitation force generated when operating at a power supply frequency of Hz.
This is a high frequency component of 00 Hz or more, which is a frequency range where vibration is particularly large, and is considered to be an important cause of noise generation. And in the present invention (solid line).

It can be seen that the vibration response level is generally lower in this frequency range, and that the part with a high vibration response level, that is, the resonant part, has moved to another frequency range (near 2000 Hz).

Figure 6 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 a frequency of around 1250Hz compared to the conventional electric compressor (dotted line). 8 As described above, the vibration isolating device for a hermetic electric compressor of the present invention accommodates an electric motor and a compression mechanism driven by the motor inside a hermetic container, and Accumulators arranged in parallel are supported by the closed container, and a curved pipe that passes through an opening provided in the end plate at the bottom of the accumulator and has a straight section inside the accumulator and is open at the upper end is connected to the refrigerant suction port of the closed container. A metal vibration isolating ring is provided in the accumulator and is connected to the inner surface of the end plate of the accumulator 7 and the curved pipe, and the vibration isolating ring is connected to the The diameter and thickness of the coupling part are set so that the resonant frequency of vibration in the coupling part moves from a frequency range of high noise to a frequency range of 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 vibration isolating ring.

[Brief explanation of drawings]

Fig. 1 is a longitudinal sectional view of a conventional hermetic electric compressor, Fig. 2 is a longitudinal sectional view of a hermetic electric compressor equipped with a vibration isolator according to an embodiment of the present invention, and Fig. 3 is a longitudinal sectional view of the same vibration isolator. Showing the vibration isolating ring that forms part of the device, (a) is a plan view, (b) is a side view, Fig. 4 is a characteristic diagram showing the vibration response characteristics of the accumulator, and Fig. 6 is a hermetic electric compressor. FIG. 3 is a characteristic diagram showing the relationship between vibration frequency and noise. 1... Airtight container, 6... Compression mechanism, 7
...Accumulator, 9...Suction port,
1o...End plate, 11...Bent pipe, 14.
...An anti-vibration ring.

Claims (2)

[Claims] (1) An electric motor and a compression mechanism driven by the electric motor are housed inside an airtight container, an accumulator arranged in parallel with the airtight container is supported by the airtight container, and the accumulator is provided on an end plate at the bottom of the accumulator. A curved pipe that penetrates the opening and has a straight section inside the accumulator and is open at the upper end is connected to the refrigerant suction port of the sealed container, and a metal barrier is connected to the inner surface of the end plate of the accumulator and the curved pipe. A vibration isolating device for a hermetic electric compressor, in which a vibration ring is provided in the accumulator. (2) A patent in which the size of the vibration isolation ring is set to a diameter and thickness such that when the electric compressor is driven, the resonance frequency of vibration in the coupling portion moves from a frequency range with high noise to a frequency range with low noise. A vibration isolation device for a hermetic electric compressor according to claim 1.