JPH01253588A - Amplitude damping device for rotary compressor - Google Patents

Abstract

PURPOSE:To reduce the fluctuation of the rotating frequencies of a rotary compressor and improve the vibration damping effect by fixing a beam type dynamic vibration reducer fixing an inertial body to a holder via a beam to an enclosed case storing a motor section and a compression element section. CONSTITUTION:A piston 6 is rotated in a cylinder 7 via a crank shaft 5 by the rotation of a rotor 4 constituting a motor together with a stator 3 stored in the enclosed case 2 of a rotary compressor, the sucked refrigerant gas is compressed by the rotation of this piston 6 and discharged to the outside. In this case, a holder 12c fittable to the outer face of the enclosed case 2 with screws 13 and a beam type dynamic vibration reducer 12 constituted of a beam 12b fixed to this holder 12c by shrinkage fitting on one end and a weight 12a fixed at the other end of this beam 12b are provided. The vibration generated during the operation of the rotary compressor is damped, the vibration reducer 12 is made removable, thus the packing at the time of transportation is facilitated.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a vibration damping device for a rotary compressor used in refrigeration equipment and the like.

BACKGROUND OF THE INVENTION In recent years, compressors used in refrigeration equipment, etc. have shifted from reciprocating type to rotary type from the viewpoint of energy and space saving, and beam type dynamic vibration absorbers have been used as vibration damping devices for rotary type compressors. It is used. As conventional technology, for example,
As shown in Japanese Patent Publication No. 68-6486, there is a vibration damping structure for a rotary hermetic electric compressor.

Hereinafter, an example of the vibration damping structure of the conventional rotary compressor mentioned above will be explained with reference to the drawings.

FIG. 2 is a partial cross-section of a conventional rotary compressor.

In the figure, 1 is a rotary compressor, and 2 is a closed case. 3 is a stator of the motor, which is fixed to the sealed case 2 with a shrink fit. 4 is a rotor of the motor, which is connected and fixed to the crankshaft 5 with a shrink fit. A piston 6 is rotatably fixed to the eccentric portion of the crankshaft 5. 7 is a cylinder with lower bearings 8 at both ends. An upper bearing 9 is provided, and the outer peripheral portion is welded and fixed to the sealed case 2. Reference numeral 10 denotes a discharge cover, which is press-fitted and fixed to the upper bearing 9. Reference numeral 11 denotes a double-beam vibration absorber, which is composed of a weight 11a and a shirt 11b with a circular cross section with the weight 11 provided at one end. Fixed. or,
The beam type dynamic vibration absorber 11 supports and fixes the rotary compressor 1, so that the natural frequency of the support system of the rotary compressor 1 itself, and the first-order natural frequency of the beam type dynamic vibration absorber 11. The maximum damping frequency caused by the rapid generation of the rotary compressor 1 is
The weight of the weight 11a is adjusted so as to almost match the rotational frequency of the weight 11a,
Shape and length of shirt) 11b.

Adjusting the diameter of the cross section.

The operation of the vibration damping device for a rotary compressor configured as described above will be described below.

When compressing the refrigerant in the cylinder 7, the pressure in the cylinder 7 fluctuates greatly during one rotation of the crankshaft, which causes fluctuations in the angular velocity of the rotation of the crankshaft 6, and as a reaction, forces are exerted on the cylinder 7, etc. receive. This causes vibrations in the torsional direction about the axis of the crankshaft 5, causing the sealed case 2 to vibrate greatly. However, by adjusting the natural frequency so that the maximum damping frequency almost matches the rotational frequency of the rotary compressor 1, the closed case 2
The weight 11a of the beam type dynamic vibration absorber 11 installed in the sealed case 2 vibrates in an opposite phase to the vibration of the closed case 2. A reaction torque is supplied to the closed case 2 through the shaft 11b of the casing 2, thereby damping vibrations.

Problems to be Solved by the Invention However, in the above configuration, the beam type dynamic vibration absorber 11
Since the peak of the natural frequency (Q value) of is sharp, the peak of the maximum damping frequency (Q value) caused by rapid formation with the natural frequency of the support system of the rotary compressor 1 itself is also sharp. Therefore, when the maximum damping frequency and the rotational frequency of the rotary compressor 1 match, the damping effect is extremely large. Due to changes in the natural frequency due to manufacturing variations, etc., the maximum damping frequency caused by coupling with the natural frequency of the support system of the rotary compressor 1 itself changes, so the maximum damping frequency and the rotary compressor 1 If the frequency difference between the rotation frequency and the rotation frequency becomes large, the vibration damping effect becomes insufficient.

Furthermore, since the beam type dynamic vibration absorber 11 protrudes 2 to the side of the rotary compressor 1 for a long time, there is a problem that the packaging during transportation becomes large and complicated.

In view of the above-mentioned problems, the present invention prevents the vibration damping effect from decreasing due to fluctuations in the rotational frequency of the rotary compressor 1 or manufacturing variations, and simplifies the packaging of the rotary compressor during transportation. A damping device is provided.

Means for Solving the Problems In order to solve the above problems, the photographic damping device for a rotary compressor of the present invention includes an electric motor section, a closed case for fixedly housing the compression element section, and a holder made of soft metal. and a beam-type dynamic vibration absorber configured by connecting an inertial body to the end opposite to the holder of the beam, and the holder of the beam-type dynamic vibration absorber is attached to the compressor body. It is fixed at .

Function: With the above-described configuration, the present invention is capable of absorbing vibrations generated during operation of a rotary compressor by a beam-type dynamic vibration absorber fixed to the rotary compressor body, which vibrates in an opposite phase to the vibrations of the rotary compressor. damping by supplying reaction torque to the co-rotating type compressor, and by fixing the beam to the holder, the damping effect of the holder can be obtained, making the vibration damping of the beam type dynamic vibration absorber effective. By widening the frequency band, it is possible to prevent the vibration damping effect from becoming insufficient due to operating conditions of the rotary compressor, variations during manufacturing, etc. Furthermore, since the beam type dynamic vibration absorber consists of a holder, a beam, and an inertial body, it is not necessary to install it when assembling the rotary compressor. can be installed in a rotary compressor, and the packaging during transportation does not become large and complicated due to the beam-forming vibration absorption a.

EXAMPLE An example of the present invention will be described below with reference to the drawings. Incidentally, in order to avoid duplication of explanation, the same parts as in the conventional example are given the same reference numerals and the explanation will be omitted.

FIG. 1 shows an embodiment of a vibration damping device for a rotary compressor according to the present invention. In the figure, 12 is a beam-type dynamic vibration absorber, which is composed of a weight 12a, a beam 12b, and a holder 12c made of soft metal such as aluminum.The weight 12a is fixed to one end of the beam 12b, and the other end is The holder 12G is fixed by shrink fitting.

Further, the holder 12C is fixed to the sealed case 2 with screws 13 so that the beam 12c is perpendicular to the sealed case 2. Furthermore, since the rotary compressor 1 is supported and fixed on the beam type dynamic vibration absorber 12, the natural frequency of the support system of the rotary compressor 1 itself and the frequency of the beam type dynamic vibration absorber 12 are determined.
so that the maximum damping frequency caused by achieving the following natural frequency almost matches the rotational frequency of the rotary compressor 1,
The weight and shape of the weight 12a, the length and cross-sectional diameter of the shaft 12b, and the shape of the holder 12c are adjusted.

The operation of the vibration damping device for a rotary compressor configured as described above will be described below.

When compressing the refrigerant in the cylinder 7, the pressure inside the cylinder 7 fluctuates greatly during one revolution of the crankshaft 6, which causes a fluctuation in the angular velocity of the rotation of the crankshaft 5, and as a reaction, the pressure inside the cylinder 7 changes greatly. Receive power. This causes vibrations in the torsional direction about the axis of the crankshaft 6, causing the sealed case 2 to vibrate greatly.

At that time, the maximum damping frequency generated by achieving the fixed-nan frequency of the beam-type dynamic vibration absorber 12 installed in the sealed case 2 and the natural frequency of the support system of the rotary compressor 1 itself is determined by the rotation of the rotary compressor 1. Since the frequency is adjusted to substantially match the frequency, the weight 12a of the beam dynamic vibration absorber 12 vibrates in the opposite phase to the vibration of the sealed case 2. Therefore, the beam 1 of the beam type dynamic vibration absorber 12
2b and a holder 12c fixed to the sealed case 2, a reaction torque is supplied to the sealed case 2 to damp vibrations of the sealed case 2. Furthermore, since the beam 12b is fixed to a holder 12c made of soft metal, the beam 12b
When b vibrates, the holder 12C deforms and vibrates minutely, so that a damping effect is obtained by the holder 12c, and the width of the peak of the natural frequency of the beam type dynamic vibration absorber 12 becomes wider (Q
value becomes larger). Therefore, the width of the peak of the maximum damping frequency caused by achieving the natural frequency of the beam dynamic vibration absorber 12 and the natural frequency of the support system of the rotary compressor 1 becomes wider (
(Q value increases), a vibration damping effect can be obtained in a wide frequency band, and the rotational frequency changes due to changes in the operating conditions of the rotary compressor 1, as well as the natural frequency during mass production of beam type dynamic vibration absorbers. A sufficient vibration damping effect can be obtained even if there is a change in the maximum damping frequency caused by variations in the vibration damping frequency. or,
When the beam type dynamic vibration absorber 12 vibrates, the holder 12 of the beam 12b
Stress will concentrate on the part fixed to the beam 12b, and there is a possibility that the fixed part of the beam 12b will fail due to fatigue during continuous excessive imaging, but the stress will be dispersed by the slight deformation of the holder 12c. , since stress will not be concentrated in one part, beam 1
The problem of fatigue failure of 2b can also be solved. In addition, the beam-type dynamic vibration absorber 12 includes a weight 12a, a beam 12b, and a holder 12c.
It is possible to assemble the beam type dynamic vibration absorber 12 after frequency adjustment as a single item, which not only improves the accuracy of frequency adjustment, but also eliminates the need to install it at the same time when assembling the rotary compressor 1. The beam-type dynamic vibration absorber 12 can be installed after the rotary compressor 1 is installed in a refrigeration system or the like, and the beam-type dynamic vibration absorber 12 does not make the packaging for transportation larger and more complicated. Furthermore, by forming the holder 12c from a soft metal, even when the beam dynamic vibration absorber 12 is placed inside the sealed case 2 of the rotary compressor 1, the holder does not deteriorate due to refrigerant, oil, temperature conditions, etc. The same stable vibration damping effect as in outside air can be obtained.

Effects of the Invention As described above, the present invention provides a closed case in which an electric motor section and a compression element section are fixedly housed, a beam fixed to a holder made of soft metal (aluminum, etc.), and a holder for the beam that is opposite to the holder. By providing a vibration damping device for a rotary compressor, which includes a beam-type dynamic vibration absorber configured by connecting an inertial body to the side end, and a holder for the beam-type dynamic vibration absorber is fixed, rotational The vibrations generated during operation of a rotary type compressor are damped by a beam type dynamic vibration absorber fixed to the compressor body, and by adding a damping effect to the beam type dynamic vibration absorber, the operating conditions of the rotary type compressor can be changed. Even if there are manufacturing variations, sufficient vibration damping effect can be obtained, and fatigue failure of the beam type dynamic vibration absorber can be prevented.Furthermore, the beam type dynamic vibration absorber can be installed outside the sealed case. Even in such cases, by separately assembling a beam-type dynamic vibration absorber and installing the beam-type dynamic vibration absorber during actual use, it is possible to prevent packaging for transportation from becoming larger and more complicated.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a vibration damping device for a rotary compressor showing an embodiment of the present invention, and FIG. 2 is a sectional view of a conventional vibration damping device for a rotary compressor. 2... Sealed case, 12... Beam type dynamic vibration absorber, 12a... Weight, 12b... Beam,
12c... Holder. Name of agent: Patent attorney Toshio Nakao and 1 other person2-
4 question case 1z --1 beam de (I force 0 sword f tatsu 2shi J2a --1 board) 2b --1 beam 12cm-1 holder 13-11 screw Fig. 1

Claims (1)

[Claims] A sealed case that fixedly houses the electric motor section and the compression element section;
A beam-type dynamic vibration absorber comprising a beam fixed to a holder made of soft metal and an inertial body connected to an end of the beam opposite to the holder, the beam-type dynamic vibration absorber A vibration damping device for a rotary compressor with a holder fixed to the compressor body.