JPS585486A - Vibration attenuator for rotary enclosed motor compressor - Google Patents

Abstract

PURPOSE:To reduce the vibration in all direction of a compressor by cancelling the torque due to the vibration of the compressor and the counter-torque from a dynamic vibration absorber. CONSTITUTION:In order to match with the rotary frequency of the compressor or the power source frequency, the dynamic vibration absorbers 4, 5 arranged in an enclosed container 1 will vibrate with the vibration of the compressor and the reverse phase. Consequently the torque due to the vibration of the compressor and the counter-action torque to be fed from the dynamic vibration absorbers 4, 5 are cancelled to provided the nod of the vibration, thereby each dynamic vibration absorbers 4, 5 will form the nod of vibration at two different points of the compressor thus to reduce the vibration in all directions of the compressor.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides vibrations in a rotary hermetic electric compressor.
: This relates to a dynamic damping structure in which multiple dynamic vibration absorbers, each consisting of a weight and a shaft with the weight attached to each end, are vertically installed on the wall of the airtight container of an electric compressor. By making the first-order natural frequency of the dynamic vibration reducer approximately equal to the rotational frequency of the electric compressor or the power supply frequency, it is possible to eliminate fluctuations in the load torque used in the compression mechanism of the hermetic electric compressor. Absorbs the vibrations generated by the electric compressor,
The present invention provides a hermetic electric compressor with low vibration.

Conventionally, the compression mechanism of a rotary hermetic electric compressor consists of suction,
In the operating process areas such as compression and discharge processes, the compressor rotates within one rotation cycle due to the gas pressure fluctuation force caused by the pressure change of the refrigerant gas, the frictional force on the sliding surfaces of each part, the inertial force of each part, and the fluctuation of electromagnetic force. Angular acceleration fluctuations occur and large vibrations are induced. However, there has been no suitable solution to the vibration caused by this load torque fluctuation force.

The present invention provides a plurality of dynamic vibration absorbers each consisting of a weight and a shaft portion provided with the weight at one end on the wall surface of the airtight container of the rotary hermetic electric compressor, protruding at right angles from a portion of the wall surface 3. By installing the dynamic vibration reducer in such a manner that the first natural frequency of the dynamic vibration absorber almost matches the rotational frequency or the power supply frequency of the electric compressor, the vibration noise of the compressor and the dynamic vibration absorber installed in the closed container can be reduced. Let's create nodes of vibration at multiple different points.

This provides a structure in which the vibrations of the compressor in all directions can be absorbed by the dynamic vibration absorber.

Hereinafter, the present invention will be described with reference to the accompanying drawings showing one embodiment thereof.

In FIG. 1, %1 is a closed container having a suction pipe 1a and a discharge pipe 1b, and inside this container there is a motor section 2 having a well-known structure and a rotary compression mechanism section 3 driven by the motor section 2. It is arranged. Reference numerals 4 and 6 denote weights 4a and 6a, respectively, and a shaft portion 4b provided at one end of the weights 4a and 5a'i.

6b, which are installed at arbitrary positions perpendicular to the wall surface of the sealed container 1 and at about 90 degrees from each other with respect to the central axis of the compressor. Here, the dynamic vibration absorbers 4 and 6 are designed with a weight 4a so that the first-order natural frequency of both of them substantially coincides with the rotational frequency of the electric compressor or the power supply frequency.

The weight of 6a, the length of shaft portion +b, ssa, cross-sectional diameter, etc. are set.

In the above configuration, when the compressor is operated, the compressor rotates at a rotational frequency slightly lower than the power supply frequency due to the speed of the electric motor, and due to the fluctuation of the load torque acting on the compression mechanism section 3 as described above, the rotation of the compressor is Large vibrations are excited at the frequency. However, since the dynamic vibration absorbers 4 and 5 installed in the sealed container 1 vibrate in the opposite phase to the vibration of the compressor so as to almost match the rotational frequency of the compressor or the power supply frequency, the dynamic vibration absorbers 4 and 6 At the installation location in the closed container 1, reaction torque is supplied to the compressor via the shaft portions 4b and 6b.

As a result, at the locations where the dynamic vibration reducers 4 and 6 are installed, the torque due to the vibration of the compressor and the reaction torque supplied from the dynamic vibration absorber 416 cancel each other out, resulting in vibration nodes. Each of the dynamic vibration absorbers 4 and 6 forms vibration nodes at two different points on the compressor to reduce vibrations in all directions of the compressor 1', -:.

Figure 3 shows how the vibration is damped.

In FIG. 3, point A is the vibration amplitude of the conventional compressor, and curve B is the vibration amplitude of the dynamic vibration absorber 4.6 in the compressor of the present invention.
Fig. 5 shows the vibration amplitude of the same compressor when the weight of a and 5a is changed.

From this result, it can be seen that by installing the dynamic vibration reducers 4 and 6 in the closed container 1, the vibration of the compressor is greatly reduced.

In addition, in the above embodiment, the shaft portion 4 of the dynamic vibration reducer 4, 6
b and 6b have a circular cross section, and the same cross-sectional area in the longitudinal direction was used, but the first natural frequency of the dynamic vibration absorber °4 and As long as the frequency is approximately the same as that of the shaft part a, any cross-sectional shape and longitudinal cross-sectional area are not particularly limited.
The length of b and esb and the weight of the weights 4a and 5a are also not particularly limited. Further, the installation location in the closed container 1 is not particularly limited either.

As is clear from the above embodiments, the vibration damping structure of the rotary hermetic electric compressor of the present invention is a dynamic vibration damping structure consisting of a weight perpendicular to the wall surface of the hermetic container and a shaft portion with the weight provided at one end. This system has a structure in which multiple dynamic vibration absorbers are installed, and the first natural frequency of each of these dynamic vibration absorbers approximately matches the rotational frequency of the electric compressor or the power supply frequency, and the structure is relatively simple. This has the advantage that machine vibration can be reduced, and by installing a plurality of vibration absorbers, vibrations in all directions can be reduced and the vibration damping effect is large.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway perspective view of a rotary hermetic electric compressor equipped with a vibration damping structure according to an embodiment of the present invention, and FIG.
The figure is a plan view of the same compressor, and FIG. 3 is a characteristic diagram showing the damping state of vibration amplitude by the dynamic vibration absorber in the same compressor. 1...--Airtight container, 2...--Electric motor section, 3
...Compression mechanism section, 4, 6...--Dynamic vibration absorber, 4a, 6a...--Heavy, weight, 4b, 6b...
...shaft part. Name of agent: Patent attorney Toshio Nakao and one other WA
II! 1 4 Seihaku No. 2r! ! J it 11

Claims (1)

[Claims] (1) In a rotary hermetic electric compressor in which an electric motor and a compression mechanism driven by the electric motor are disposed inside a hermetic container, a weight is attached to the wall of the airtight container and the weight is attached to one end of the rotary hermetic electric compressor. A plurality of dynamic vibration absorbers each consisting of a shaft section are installed perpendicularly to the wall surface of the sealed container, and the first natural frequency of the dynamic vibration absorber is set to the rotational frequency of the electric compressor or , a vibration damping structure for a rotary hermetic electric compressor that nearly matches the power supply frequency. Vibration damping of a rotary hermetic electric compressor according to claim 1, wherein the dynamic vibration absorbers are installed so that they protrude from each other at an angle of about 90 with respect to the center axis of the compressor. structure.